88fca45...main · reshape

git.iko.soy/reshape

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.github/workflows/lint.yaml+3−3

since splitsnapshots

unifiedsplit

@@ -15,7 +15,7 @@ jobs:

15 runs-on: ubuntu-latest

16 steps:

17 - name: Checkout

18− uses: actions/checkout@v2

18+ uses: actions/checkout@v4

19 - name: Select Rust toolchain with Clippy

20 uses: actions-rs/toolchain@v1

21 with:

@@ -23,6 +23,6 @@ jobs:

23 components: clippy

24 override: true

25 - name: Use cache for Rust dependencies

26− uses: Swatinem/rust-cache@v1

26+ uses: Swatinem/rust-cache@v2

27 - name: Lint using Clippy

28− run: cargo clippy

28+ run: cargo clippy

.github/workflows/publish-crate.yamlnew file+20

@@ -0,0 +1,20 @@

1+name: Publish crate

3+on: workflow_dispatch

5+jobs:

6+ publish-crate:

7+ runs-on: ubuntu-latest

8+ steps:

9+ - name: Checkout

10+ uses: actions/checkout@v2

11+ - name: Select Rust toolchain

12+ uses: actions-rs/toolchain@v1

13+ with:

14+ toolchain: stable

15+ - name: Publish to crates.io

16+ uses: actions-rs/cargo@v1

17+ with:

18+ command: publish

19+ env:

20+ CARGO_REGISTRY_TOKEN: ${{ secrets.CRATES_IO_TOKEN }}

.github/workflows/publish-docker.yamlnew file+25

@@ -0,0 +1,25 @@

1+name: Publish Docker image

3+on:

4+ workflow_dispatch:

5+ inputs:

6+ version:

7+ description: "Version (without 'v' prefix)"

8+ required: true

9+ type: string

10+

11+jobs:

12+ publish-docker:

13+ runs-on: ubuntu-latest

14+ steps:

15+ - name: Checkout

16+ uses: actions/checkout@v2

17+ - name: Log in to Docker

18+ env:

19+ DOCKER_PASSWORD: ${{ secrets.DOCKER_ACCESS_TOKEN }}

20+ run: |

21+ docker login -u ${{ secrets.DOCKER_USER }} -p $DOCKER_PASSWORD

22+ - name: Build Docker image

23+ run: docker build . --tag ${{ secrets.DOCKER_USER }}/reshape:${{ inputs.version }} --tag ${{ secrets.DOCKER_USER }}/reshape:latest

24+ - name: Push Docker image

25+ run: docker push --all-tags ${{ secrets.DOCKER_USER }}/reshape

Cargo.toml+4−3

@@ -1,6 +1,6 @@

1[package]

2name = "reshape"

3−version = "0.5.1"

3+version = "0.7.0"

4description = "An easy-to-use, zero-downtime schema migration tool for Postgres"

5homepage = "https://github.com/fabianlindfors/reshape"

6documentation = "https://github.com/fabianlindfors/reshape"

@@ -9,7 +9,7 @@ license = "MIT"

9keywords = ["postgres", "migrations"]

10edition = "2021"

11authors = ["Fabian Lindfors"]

12−rust-version = "1.58"

12+rust-version = "1.70"

14[dependencies]

15postgres = { version = "0.19.2", features = ["with-serde_json-1"] }

@@ -22,4 +22,5 @@ toml = "0.5"

22version = "3.0.0"

23colored = "2"

24rand = "0.8"

25−dotenv = "0.15.0"

25+dotenv = "0.15.0"

26+lexical-sort = "0.3.1"

Dockerfile+1−1

@@ -1,4 +1,4 @@

1−FROM rust:1.58.0 AS builder

1+FROM rust:1.70.0 AS builder

2WORKDIR /usr/src/reshape

3COPY . .

4RUN cargo build --release

README.md+246−97

@@ -2,56 +2,56 @@

3[![Test status badge](https://github.com/fabianlindfors/Reshape/actions/workflows/test.yaml/badge.svg)](https://github.com/fabianlindfors/reshape/actions/workflows/test.yaml) [![Latest release](https://shields.io/github/v/release/fabianlindfors/reshape?display_name=tag&sort=semver&color=blue)](https://github.com/fabianlindfors/reshape/releases)

5+> Also check out [ReshapeDB](https://reshapedb.com), a new database built from the ground up to make zero-downtime schema and data migrations as simple and safe as possible. If you'd like to chat about it, please [reach out](contact@reshapedb.com)!

5Reshape is an easy-to-use, zero-downtime schema migration tool for Postgres. It automatically handles complex migrations that would normally require downtime or manual multi-step changes. During a migration, Reshape ensures both the old and new schema are available at the same time, allowing you to gradually roll out your application. It will also perform all changes without excessive locking, avoiding downtime caused by blocking other queries. For a more thorough introduction to Reshape, check out the [introductory blog post](https://fabianlindfors.se/blog/schema-migrations-in-postgres-using-reshape/).

7Reshape is an easy-to-use, zero-downtime schema migration tool for Postgres. It automatically handles complex migrations that would normally require downtime or manual multi-step changes. During a migration, Reshape ensures both the old and new schema are available at the same time, allowing you to gradually roll out your application. It will also perform all changes without excessive locking, avoiding downtime caused by blocking other queries. For a more thorough introduction to Reshape, check out the [introductory blog post](https://fabianlindfors.se/blog/schema-migrations-in-postgres-using-reshape/).

7Designed for Postgres 12 and later.

9Designed for Postgres 12 and later.

9−*Note: Reshape is **experimental** and should not be used in production. It can (and probably will) break your application.*

10−

11- [How it works](#how-it-works)

12- [Getting started](#getting-started)

13− - [Installation](#installation)

13+ - [Installation](#installation)

14− - [Creating your first migration](#creating-your-first-migration)

14+ - [Creating your first migration](#creating-your-first-migration)

15− - [Preparing your application](#preparing-your-application)

15+ - [Preparing your application](#preparing-your-application)

16− - [Running your migration](#running-your-migration)

16+ - [Running your migration](#running-your-migration)

17− - [Using during development](#using-during-development)

17+ - [Using during development](#using-during-development)

18- [Writing migrations](#writing-migrations)

19− - [Basics](#basics)

19+ - [Basics](#basics)

20− - [Tables](#tables)

20+ - [Tables](#tables)

21− - [Create table](#create-table)

21+ - [Create table](#create-table)

22− - [Rename table](#rename-table)

22+ - [Rename table](#rename-table)

23− - [Remove table](#remove-table)

23+ - [Remove table](#remove-table)

24− - [Add foreign key](#add-foreign-key)

24+ - [Add foreign key](#add-foreign-key)

25− - [Remove foreign key](#remove-foreign-key)

25+ - [Remove foreign key](#remove-foreign-key)

26− - [Columns](#columns)

26+ - [Columns](#columns)

27− - [Add column](#add-column)

27+ - [Add column](#add-column)

28− - [Alter column](#alter-column)

28+ - [Alter column](#alter-column)

29− - [Remove column](#remove-column)

29+ - [Remove column](#remove-column)

30− - [Indices](#indices)

30+ - [Indices](#indices)

31− - [Add index](#add-index)

31+ - [Add index](#add-index)

32− - [Remove index](#remove-index)

32+ - [Remove index](#remove-index)

33− - [Enums](#enums)

33+ - [Enums](#enums)

34− - [Create enum](#create-enum)

34+ - [Create enum](#create-enum)

35− - [Remove enum](#remove-enum)

35+ - [Remove enum](#remove-enum)

36− - [Custom](#custom)

36+ - [Custom](#custom)

37+ - [Complex changes across tables](#complex-changes-across-tables)

37- [Commands and options](#commands-and-options)

38- [Commands and options](#commands-and-options)

38− - [`reshape migrate`](#reshape-migrate)

39+ - [`reshape migration start`](#reshape-migration-start)

39− - [`reshape complete`](#reshape-complete)

40+ - [`reshape migration complete`](#reshape-migration-complete)

40− - [`reshape abort`](#reshape-abort)

41+ - [`reshape migration abort`](#reshape-migration-abort)

41− - [`reshape generate-schema-query`](#reshape-generate-schema-query)

42+ - [`reshape schema-query`](#reshape-schema-query)

42− - [Connection options](#connection-options)

43+ - [Connection options](#connection-options)

43- [License](#license)

44- [License](#license)

45−

46## How it works

48Reshape works by creating views that encapsulate the underlying tables, which your application will interact with. During a migration, Reshape will automatically create a new set of views and set up triggers to translate inserts and updates between the old and new schema. This means that every deployment is a three-phase process:

50−1. **Start migration** (`reshape migrate`): Sets up views and triggers to ensure both the new and old schema are usable at the same time.

50+1. **Start migration** (`reshape migration start`): Sets up views and triggers to ensure both the new and old schema are usable at the same time.

512. **Roll out application**: Your application can be gradually rolled out without downtime. The existing deployment will continue using the old schema whilst the new deployment uses the new schema.

52−3. **Complete migration** (`reshape complete`): Removes the old schema and any intermediate data and triggers.

52+3. **Complete migration** (`reshape migration complete`): Removes the old schema and any intermediate data and triggers.

54−If the application deployment fails, you should run `reshape abort` which will roll back any changes made by `reshape migrate` without losing data.

54+If the application deployment fails, you should run `reshape migration abort` which will roll back any changes made by `reshape migration start` without losing data.

56## Getting started

@@ -71,10 +71,10 @@ cargo install reshape

72#### Docker

74−Reshape is available as a Docker image on [Docker Hub](https://hub.docker.com/repository/docker/fabianlindfors/reshape).

74+Reshape is available as a Docker image on [Docker Hub](https://hub.docker.com/repository/docker/fabianlindfors/reshape).

76```shell

77−docker run -v $(pwd):/usr/share/app fabianlindfors/reshape reshape migrate

77+docker run -v $(pwd):/usr/share/app fabianlindfors/reshape reshape migration start

78```

80### Creating your first migration

@@ -103,9 +103,14 @@ This is the equivalent of running `CREATE TABLE users (id INTEGER GENERATED ALWA

103

104### Preparing your application

105

106−Reshape relies on your application using a specific schema. When establishing the connection to Postgres in your application, you need to run a query to select the most recent schema. This query can be generated using: `reshape generate-schema-query`.

106+Reshape relies on your application using a specific schema. When establishing the connection to Postgres in your application, you need to run a query to select the most recent schema. The simplest way to do this is to use one of the helper libraries:

107

108+- [Rust](https://github.com/fabianlindfors/reshape-helper)

109+- [Ruby (and Rails)](https://github.com/fabianlindfors/reshape-ruby)

110+- [Python (and Django)](https://github.com/fabianlindfors/reshape-python)

111+- [Go](https://github.com/leourbina/reshape-helper)

112+

108−To pass it along to your application, you can for example use an environment variable in your run script: `RESHAPE_SCHEMA_QUERY=$(reshape generate-schema-query)`. Then in your application:

113+If your application is not using one of the languages with an available helper library, you can instead generate the query with the command: `reshape schema-query`. To pass it along to your application, you can for example use an environment variable in your run script: `RESHAPE_SCHEMA_QUERY=$(reshape schema-query)`. Then in your application:

109

114

110```python

115```python

111# Example for Python

116# Example for Python

@@ -113,23 +118,21 @@ reshape_schema_query = os.getenv("RESHAPE_SCHEMA_QUERY")

113db.execute(reshape_schema_query)

118db.execute(reshape_schema_query)

114```

119```

115

120

116−If your application is written in Rust, you might prefer the [Rust helper library](https://github.com/fabianlindfors/reshape-helper) which embeds the query directly in your application with a macro.

117−

118### Running your migration

121### Running your migration

119

122

120To create your new `users` table, run:

123To create your new `users` table, run:

121

124

122```bash

125```bash

123−reshape migrate --complete

126+reshape migration start --complete

124```

127```

125

128

126−We use the `--complete` flag to automatically complete the migration. During a production deployment, you should first run `reshape migrate` followed by `reshape complete` once your application has been fully rolled out.

129+We use the `--complete` flag to automatically complete the migration. During a production deployment, you should first run `reshape migration start` followed by `reshape migration complete` once your application has been fully rolled out.

127

130

128If nothing else is specified, Reshape will try to connect to a Postgres database running on `localhost` using `postgres` as both username and password. See [Connection options](#connection-options) for details on how to change the connection settings.

131If nothing else is specified, Reshape will try to connect to a Postgres database running on `localhost` using `postgres` as both username and password. See [Connection options](#connection-options) for details on how to change the connection settings.

129

132

130### Using during development

133### Using during development

131

134

132−When adding new migrations during development, we recommend running `reshape migrate` but skipping `reshape complete`. This way, the new migrations can be iterated on by updating the migration file and running `reshape abort` followed by `reshape migrate`.

135+When adding new migrations during development, we recommend running `reshape migration start` but skipping `reshape migration complete`. This way, the new migrations can be iterated on by updating the migration file and running `reshape migration abort` followed by `reshape migration start`.

133

136

134## Writing migrations

137## Writing migrations

135

138

@@ -164,9 +167,9 @@ Every action has a `type`. The supported types are detailed below.

164

167

165#### Create table

168#### Create table

166

169

167−The `create_table` action will create a new table with the specified columns, indices and constraints.

170+The `create_table` action will create a new table with the specified columns, indices and constraints. You can optionally provide an `up` option to backfill values from an existing table.

168

171

169−*Example: create a `customers` table with a few columns and a primary key*

172+_Example: create a `customers` table with a few columns and a primary key_

170

173

171```toml

174```toml

172[[actions]]

175[[actions]]

@@ -184,13 +187,13 @@ primary_key = ["id"]

184 type = "TEXT"

187 type = "TEXT"

185

188

186 # Columns default to nullable

189 # Columns default to nullable

187− nullable = false

190+ nullable = false

188

191

189 # default can be any valid SQL value, in this case a string literal

192 # default can be any valid SQL value, in this case a string literal

190− default = "'PLACEHOLDER'"

193+ default = "'PLACEHOLDER'"

191```

194```

192

195

193−*Example: create `users` and `items` tables with a foreign key between them*

196+_Example: create `users` and `items` tables with a foreign key between them_

194

197

195```toml

198```toml

196[[actions]]

199[[actions]]

@@ -223,11 +226,34 @@ primary_key = ["id"]

223 referenced_columns = ["id"]

226 referenced_columns = ["id"]

224```

227```

225

228

229+_Example: create `profiles` table based on existing `users` table_

230+

231+```toml

232+[[actions]]

233+type = "create_table"

234+name = "profiles"

235+primary_key = ["user_id"]

236+

237+ [[actions.columns]]

238+ name = "user_id"

239+ type = "INTEGER"

240+

241+ [[actions.columns]]

242+ name = "user_email"

243+ type = "TEXT"

244+

245+ # Backfill from `users` table and copy `users.email` to `user_email` column

246+ # This will perform an upsert based on the primary key to avoid duplicate rows

247+ [actions.up]

248+ table = "users"

249+ values = { user_id = "id", user_email = "email" }

250+```

251+

226#### Rename table

252#### Rename table

227

253

228The `rename_table` action will change the name of an existing table.

254The `rename_table` action will change the name of an existing table.

229

255

230−*Example: change name of `users` table to `customers`*

256+_Example: change name of `users` table to `customers`_

231

257

232```toml

258```toml

233[[actions]]

259[[actions]]

@@ -240,7 +266,7 @@ new_name = "customers"

240

266

241The `remove_table` action will remove an existing table.

267The `remove_table` action will remove an existing table.

242

268

243−*Example: remove `users` table*

269+_Example: remove `users` table_

244

270

245```toml

271```toml

246[[actions]]

272[[actions]]

@@ -252,7 +278,7 @@ table = "users"

252

278

253The `add_foreign_key` action will add a foreign key between two existing tables. The migration will fail if the existing column values aren't valid references.

279The `add_foreign_key` action will add a foreign key between two existing tables. The migration will fail if the existing column values aren't valid references.

254

280

255−*Example: create foreign key from `items` to `users` table*

281+_Example: create foreign key from `items` to `users` table_

256

282

257```toml

283```toml

258[[actions]]

284[[actions]]

@@ -269,7 +295,7 @@ table = "items"

269

295

270The `remove_foreign_key` action will remove an existing foreign key. The foreign key will only be removed once the migration is completed, which means that your new application must continue to adhere to the foreign key constraint.

296The `remove_foreign_key` action will remove an existing foreign key. The foreign key will only be removed once the migration is completed, which means that your new application must continue to adhere to the foreign key constraint.

271

297

272−*Example: remove foreign key `items_user_id_fkey` from `users` table*

298+_Example: remove foreign key `items_user_id_fkey` from `users` table_

273

299

274```toml

300```toml

275[[actions]]

301[[actions]]

@@ -282,9 +308,9 @@ foreign_key = "items_user_id_fkey"

282

308

283#### Add column

309#### Add column

284

310

285−The `add_column` action will add a new column to an existing table. You can optionally provide an `up` setting. This should be an SQL expression which will be run for all existing rows to backfill the new column.

311+The `add_column` action will add a new column to an existing table. You can optionally provide an `up` setting. This should be an SQL expression which will be run for all existing rows to backfill the new column. `up` may also reference another table to perform cross-table migrations (see ["Complex changes across tables"](#complex-changes-across-tables)).

286

312

287−*Example: add a new column `reference` to table `products`*

313+_Example: add a new column `reference` to table `products`_

288

314

289```toml

315```toml

290[[actions]]

316[[actions]]

@@ -298,7 +324,7 @@ table = "products"

298 default = "10"

324 default = "10"

299```

325```

300

326

301−*Example: replace an existing `name` column with two new columns, `first_name` and `last_name`*

327+_Example: replace an existing `name` column with two new columns, `first_name` and `last_name`_

302

328

303```toml

329```toml

304[[actions]]

330[[actions]]

@@ -334,7 +360,7 @@ column = "name"

334down = "first_name || ' ' || last_name"

360down = "first_name || ' ' || last_name"

335```

361```

336

362

337−*Example: extract nested value from unstructured JSON `data` column to new `name` column*

363+_Example: extract nested value from unstructured JSON `data` column to new `name` column_

338

364

339```toml

365```toml

340[[actions]]

366[[actions]]

@@ -349,6 +375,25 @@ up = "data['path']['to']['value'] #>> '{}'"

349 type = "TEXT"

375 type = "TEXT"

350```

376```

351

377

378+_Example: duplicate `email` column from `users` to `profiles` table_

379+

380+```toml

381+# `profiles` has `user_id` column which maps to `users.id`

382+[[actions]]

383+type = "add_column"

384+table = "profiles"

385+

386+ [actions.column]

387+ name = "email"

388+ type = "TEXT"

389+ nullable = false

390+

391+ # When `users` is updated in the old schema, we write the email value to `profiles`

392+ [actions.up]

393+ table = "users"

394+ value = "email"

395+ where = "user_id = id"

396+```

352

397

353#### Alter column

398#### Alter column

354

399

@@ -356,7 +401,7 @@ The `alter_column` action enables many different changes to an existing column,

356

401

357When performing more complex changes than a rename, `up` and `down` should be provided. These should be SQL expressions which determine how to transform between the new and old version of the column. Inside those expressions, you can reference the current column value by the column name.

402When performing more complex changes than a rename, `up` and `down` should be provided. These should be SQL expressions which determine how to transform between the new and old version of the column. Inside those expressions, you can reference the current column value by the column name.

358

403

359−*Example: rename `last_name` column on `users` table to `family_name`*

404+_Example: rename `last_name` column on `users` table to `family_name`_

360

405

361```toml

406```toml

362[[actions]]

407[[actions]]

@@ -368,7 +413,7 @@ column = "last_name"

368 name = "family_name"

413 name = "family_name"

369```

414```

370

415

371−*Example: change the type of `reference` column from `INTEGER` to `TEXT`*

416+_Example: change the type of `reference` column from `INTEGER` to `TEXT`_

372

417

373```toml

418```toml

374[[actions]]

419[[actions]]

@@ -383,7 +428,7 @@ down = "CAST(reference AS INTEGER)" # Converts from text value to integer

383 type = "TEXT" # Previous type was 'INTEGER'

428 type = "TEXT" # Previous type was 'INTEGER'

384```

429```

385

430

386−*Example: increment all values of an `index` column by one*

431+_Example: increment all values of an `index` column by one_

387

432

388```toml

433```toml

389[[actions]]

434[[actions]]

@@ -398,7 +443,7 @@ down = "index - 1" # Decrement to revert for old schema

398 name = "index"

443 name = "index"

399```

444```

400

445

401−*Example: make `name` column not nullable*

446+_Example: make `name` column not nullable_

402

447

403```toml

448```toml

404[[actions]]

449[[actions]]

@@ -413,7 +458,7 @@ up = "COALESCE(name, 'N/A')"

413 nullable = false

458 nullable = false

414```

459```

415

460

416−*Example: change default value of `created_at` column to current time*

461+_Example: change default value of `created_at` column to current time_

417

462

418```toml

463```toml

419[[actions]]

464[[actions]]

@@ -427,11 +472,11 @@ column = "created_at"

427

472

428#### Remove column

473#### Remove column

429

474

430−The `remove_column` action will remove an existing column from a table. You can optionally provide a `down` setting. This should be an SQL expression which will be used to determine values for the old schema when inserting or updating rows using the new schema. The `down` setting must be provided when the removed column is `NOT NULL` or doesn't have a default value.

475+The `remove_column` action will remove an existing column from a table. You can optionally provide a `down` setting. This should be an SQL expression which will be used to determine values for the old schema when inserting or updating rows using the new schema. `down` may also reference another table to perform cross-table migrations (see ["Complex changes across tables"](#complex-changes-across-tables)) . The `down` setting must be provided when the removed column is `NOT NULL` or doesn't have a default value.

431

476

432Any indices that cover the column will be removed.

477Any indices that cover the column will be removed.

433

478

434−*Example: remove column `name` from table `users`*

479+_Example: remove column `name` from table `users`_

435

480

436```toml

481```toml

437[[actions]]

482[[actions]]

@@ -443,18 +488,34 @@ column = "name"

443down = "'N/A'"

488down = "'N/A'"

444```

489```

445

490

491+_Example: remove `email` column from `users` table and use column from `profiles` table instead_

492+

493+```toml

494+[[actions]]

495+type = "remove_column"

496+table = "users"

497+column = "email"

498+

499+ # Our application will use the `profiles.email` column instead

500+ # For backwards compatibility, we will write back to the removed `email` column whenever `profiles` is changed

501+ [actions.down]

502+ table = "profiles"

503+ value = "profiles.email"

504+ where = "users.id = profiles.user_id"

505+```

506+

446### Indices

507### Indices

447

508

448#### Add index

509#### Add index

449

510

450The `add_index` action will add a new index to an existing table.

511The `add_index` action will add a new index to an existing table.

451

512

452−*Example: create a `users` table with a unique index on the `name` column*

513+_Example: create a `users` table with a unique index on the `name` column_

453

514

454```toml

515```toml

455[[actions]]

516[[actions]]

456type = "create_table"

517type = "create_table"

457−table = "users"

518+name = "users"

458primary_key = "id"

519primary_key = "id"

459

520

460 [[actions.columns]]

521 [[actions.columns]]

@@ -478,7 +539,7 @@ table = "users"

478 unique = true

539 unique = true

479```

540```

480

541

481−*Example: add GIN index to `data` column on `products` table*

542+_Example: add GIN index to `data` column on `products` table_

482

543

483```toml

544```toml

484[[actions]]

545[[actions]]

@@ -497,7 +558,7 @@ table = "products"

497

558

498The `remove_index` action will remove an existing index. The index won't actually be removed until the migration is completed.

559The `remove_index` action will remove an existing index. The index won't actually be removed until the migration is completed.

499

560

500−*Example: remove the `name_idx` index*

561+_Example: remove the `name_idx` index_

501

562

502```toml

563```toml

503[[actions]]

564[[actions]]

@@ -511,7 +572,7 @@ index = "name_idx"

511

572

512The `create_enum` action will create a new [enum type](https://www.postgresql.org/docs/current/datatype-enum.html) with the specified values.

573The `create_enum` action will create a new [enum type](https://www.postgresql.org/docs/current/datatype-enum.html) with the specified values.

513

574

514−*Example: add a new `mood` enum type with three possible values*

575+_Example: add a new `mood` enum type with three possible values_

515

576

516```toml

577```toml

517[[actions]]

578[[actions]]

@@ -524,7 +585,7 @@ values = ["happy", "ok", "sad"]

524

585

525The `remove_enum` action will remove an existing [enum type](https://www.postgresql.org/docs/current/datatype-enum.html). Make sure all usages of the enum has been removed before running the migration. The enum will only be removed once the migration is completed.

586The `remove_enum` action will remove an existing [enum type](https://www.postgresql.org/docs/current/datatype-enum.html). Make sure all usages of the enum has been removed before running the migration. The enum will only be removed once the migration is completed.

526

587

527−*Example: remove the `mood` enum type*

588+_Example: remove the `mood` enum type_

528

589

529```toml

590```toml

530[[actions]]

591[[actions]]

@@ -538,11 +599,11 @@ The `custom` action lets you create a migration which runs custom SQL. It should

538

599

539There are three optional settings available which all accept SQL queries. All queries need to be idempotent, for example by using `IF NOT EXISTS` wherever available.

600There are three optional settings available which all accept SQL queries. All queries need to be idempotent, for example by using `IF NOT EXISTS` wherever available.

540

601

541−- `start`: run when a migration is started using `reshape migrate`

602+- `start`: run when a migration is started using `reshape migration start`

542−- `complete`: run when a migration is completed using `reshape complete`

603+- `complete`: run when a migration is completed using `reshape migration complete`

543−- `abort`: run when a migration is aborted using `reshape abort`

604+- `abort`: run when a migration is aborted using `reshape migration abort`

544

605

545−*Example: enable PostGIS and pg_stat_statements extensions*

606+_Example: enable PostGIS and pg_stat_statements extensions_

546

607

547```toml

608```toml

548[[actions]]

609[[actions]]

@@ -554,52 +615,140 @@ start = """

554"""

615"""

555

616

556abort = """

617abort = """

557− DROP EXTENSION IF NOT EXISTS postgis;

618+ DROP EXTENSION IF EXISTS postgis;

558− DROP EXTENSION IF NOT EXISTS pg_stat_statements;

619+ DROP EXTENSION IF EXISTS pg_stat_statements;

559"""

620"""

560```

621```

561

622

623+### Complex changes across tables

624+

625+The `up` and `down` options available when creating tables, adding columns and removing columns can also perform more complex changes that span tables.

626+

627+_Example: move `email` column from `users` to `profiles` table_

628+

629+```toml

630+[[actions]]

631+type = "add_column"

632+table = "profiles"

633+

634+ [actions.column]

635+ name = "email"

636+ type = "TEXT"

637+ nullable = false

638+

639+ # When `users` is updated in the old schema, we write the email value to `profiles`

640+ [actions.up]

641+ table = "users"

642+ value = "users.email"

643+ where = "profiles.user_id = users.id"

644+

645+[[actions]]

646+type = "remove_column"

647+table = "users"

648+column = "email"

649+

650+ # When `profiles` is changed in the new schema, we write the email address back to the removed column

651+ [actions.down]

652+ table = "profiles"

653+ value = "profiles.email"

654+ where = "users.id = profiles.user_id"

655+```

656+

657+_Example: turn a 1:N relationship between `users` and `accounts` into N:M and change the format of the associated `role`_

658+

659+```toml

660+# Add `user_account_connections` as a junction table

661+[[actions]]

662+type = "create_table"

663+name = "user_account_connections"

664+primary_key = ["account_id", "user_id"]

665+

666+ [[actions.columns]]

667+ name = "account_id"

668+ type = "INTEGER"

669+

670+ [[actions.columns]]

671+ name = "user_id"

672+ type = "INTEGER"

673+

674+ # `role` is currently stored directly on the `users` table but is part of the relationship

675+ [[actions.columns]]

676+ name = "role"

677+ type = "TEXT"

678+ nullable = false

679+

680+ # Backfill the new table from `users` and uppercase the `role`

681+ [actions.up]

682+ table = "users"

683+ values = { user_id = "id", account_id = "account_id", role = "UPPER(account_role)" }

684+ where = "user_account_connections.user_id = users.id"

685+

686+[[actions]]

687+type = "remove_column"

688+table = "users"

689+column = "account_id"

690+

691+ # When `user_account_connections` is updated, we write the `account_id` back to `users`

692+ [actions.down]

693+ table = "user_account_connections"

694+ value = "user_account_connections.account_id"

695+ where = "users.id = user_account_connections.user_id"

696+

697+[[actions]]

698+type = "remove_column"

699+table = "users"

700+column = "account_role"

701+

702+ # When `user_account_connections` is updated, we write the lowercase role back to `users`

703+ [actions.down]

704+ table = "user_account_connections"

705+ value = "LOWER(user_account_connections.role)"

706+ where = "users.id = user_account_connections.user_id"

707+```

708+

562## Commands and options

709## Commands and options

563

710

564−### `reshape migrate`

711+### `reshape migration start`

565

712

566−Starts a new migration, applying all migrations under `migrations/` that haven't yet been applied. After the command has completed, both the old and new schema will be usable at the same time. When you have rolled out the new version of your application which uses the new schema, you should run `reshape complete`.

713+Starts a new migration, applying all migrations under `migrations/` that haven't yet been applied. After the command has completed, both the old and new schema will be usable at the same time. When you have rolled out the new version of your application which uses the new schema, you should run `reshape migration complete`.

567

714

568#### Options

715#### Options

569

716

570−*See also [Connection options](#connection-options)*

717+_See also [Connection options](#connection-options)_

571

718

572−| Option | Default | Description |

719+| Option | Default | Description |

573−| ------ | ------- | ----------- |

720+| ------------------ | ------------- | --------------------------------------------------------------------------------------------------------------- |

574−| `--complete`, `-c` | `false` | Automatically complete migration after applying it. |

721+| `--complete`, `-c` | `false` | Automatically complete migration after applying it. |

575−| `--dirs` | `migrations/` | Directories to search for migration files. Multiple directories can be specified using `--dirs dir1 dir2 dir3`. |

722+| `--dirs` | `migrations/` | Directories to search for migration files. Multiple directories can be specified using `--dirs dir1 dir2 dir3`. |

576

723

577−### `reshape complete`

724+### `reshape migration complete`

578

725

579−Completes migrations previously started with `reshape complete`.

726+Completes migrations previously started with `reshape migration complete`.

580

727

581#### Options

728#### Options

582

729

583See [Connection options](#connection-options)

730See [Connection options](#connection-options)

584

731

585−### `reshape abort`

732+### `reshape migration abort`

586

733

587−Aborts any migrations which haven't yet been completed.

734+Aborts any migrations which haven't yet been completed.

588

735

589#### Options

736#### Options

590

737

591See [Connection options](#connection-options)

738See [Connection options](#connection-options)

592

739

593−### `reshape generate-schema-query`

740+### `reshape schema-query`

594

741

595Generates the SQL query you need to run in your application before using the database. This command does not require a database connection. Instead it will generate the query based on the latest migration in the `migrations/` directory (or the directories specified by `--dirs`).

742Generates the SQL query you need to run in your application before using the database. This command does not require a database connection. Instead it will generate the query based on the latest migration in the `migrations/` directory (or the directories specified by `--dirs`).

596

743

744+If your application is written in Rust, we recommend using the [Rust helper library](https://github.com/fabianlindfors/reshape-helper/) instead.

745+

597The query should look something like `SET search_path TO migration_1_initial_migration`.

746The query should look something like `SET search_path TO migration_1_initial_migration`.

598

747

599#### Options

748#### Options

600

749

601−| Option | Default | Description |

750+| Option | Default | Description |

602−| ------ | ------- | ----------- |

751+| -------- | ------------- | --------------------------------------------------------------------------------------------------------------- |

603| `--dirs` | `migrations/` | Directories to search for migration files. Multiple directories can be specified using `--dirs dir1 dir2 dir3`. |

752| `--dirs` | `migrations/` | Directories to search for migration files. Multiple directories can be specified using `--dirs dir1 dir2 dir3`. |

604

753

605### Connection options

754### Connection options

@@ -608,14 +757,14 @@ The options below can be used with all commands that communicate with Postgres.

608

757

609All options can also be set using environment variables instead of flags. If a `.env` file exists, then variables will be automatically loaded from there.

758All options can also be set using environment variables instead of flags. If a `.env` file exists, then variables will be automatically loaded from there.

610

759

612−| ------ | ------- | -------------------- | ----------- |

761+| ------------ | ----------- | -------------------- | ------------------------------------------- |

613−| `--url` | | `DB_URL` | URL to your Postgres database |

762+| `--url` | | `DB_URL` | URL to your Postgres database |

619

768

620## License

769## License

621

770

src/lib.rs+17−12

@@ -147,13 +147,15 @@ fn migrate(

147) -> anyhow::Result<()> {

148 // Make sure no migration is in progress

149 if let State::InProgress { .. } = &state {

150+ println!(

150− println!("Migration already in progress, please complete using 'reshape complete'");

151+ "Migration already in progress, please complete using 'reshape migration complete'"

152+ );

151 return Ok(());

153 return Ok(());

152 }

154 }

153

155

154 if let State::Completing { .. } = &state {

156 if let State::Completing { .. } = &state {

155 println!(

157 println!(

156− "Migration already in progress and has started completion, please finish using 'reshape complete'"

158+ "Migration already in progress and has started completion, please finish using 'reshape migration complete'"

157 );

159 );

158 return Ok(());

160 return Ok(());

159 }

161 }

@@ -176,7 +178,7 @@ fn migrate(

176 {

178 {

177 if existing_migrations != &remaining_migrations {

179 if existing_migrations != &remaining_migrations {

178 return Err(anyhow!(

180 return Err(anyhow!(

179− "a previous migration seems to have failed without cleaning up. Please run `reshape abort` and then run migrate again."

181+ "a previous migration seems to have failed without cleaning up. Please run `reshape migration abort` and then run migrate again."

180 ));

182 ));

181 }

183 }

182 }

184 }

@@ -198,7 +200,7 @@ fn migrate(

198 let mut last_action_index = usize::MAX;

200 let mut last_action_index = usize::MAX;

199 let mut result: anyhow::Result<()> = Ok(());

201 let mut result: anyhow::Result<()> = Ok(());

200

202

201− for (migration_index, migration) in remaining_migrations.iter().enumerate() {

203+ 'outer: for (migration_index, migration) in remaining_migrations.iter().enumerate() {

202 println!("Migrating '{}':", migration.name);

204 println!("Migrating '{}':", migration.name);

203 last_migration_index = migration_index;

205 last_migration_index = migration_index;

204

206

@@ -208,7 +210,8 @@ fn migrate(

208 let description = action.describe();

210 let description = action.describe();

209 print!(" + {} ", description);

211 print!(" + {} ", description);

210

212

213+ let ctx =

211− let ctx = MigrationContext::new(migration_index, action_index);

214+ MigrationContext::new(migration_index, action_index, state::current_migration(db)?);

212 result = action

215 result = action

213 .run(&ctx, db, &new_schema)

216 .run(&ctx, db, &new_schema)

214 .with_context(|| format!("failed to {}", description));

217 .with_context(|| format!("failed to {}", description));

@@ -218,7 +221,7 @@ fn migrate(

218 println!("{}", "done".green());

221 println!("{}", "done".green());

219 } else {

222 } else {

220 println!("{}", "failed".red());

223 println!("{}", "failed".red());

221− break;

224+ break 'outer;

222 }

225 }

223 }

226 }

224

227

@@ -232,7 +235,7 @@ fn migrate(

232 // Set to the Aborting state. This is to ensure that the failed

235 // Set to the Aborting state. This is to ensure that the failed

233 // migration is fully aborted and nothing is left dangling.

236 // migration is fully aborted and nothing is left dangling.

234 // If the abort is interrupted for any reason, the user can try again

237 // If the abort is interrupted for any reason, the user can try again

235− // by running `reshape abort`.

238+ // by running `reshape migration abort`.

236 state.aborting(

239 state.aborting(

237 remaining_migrations.clone(),

240 remaining_migrations.clone(),

238 last_migration_index + 1,

241 last_migration_index + 1,

@@ -259,7 +262,7 @@ fn migrate(

259 schema_query_for_migration(&target_migration)

262 schema_query_for_migration(&target_migration)

260 );

263 );

261 println!(

264 println!(

262− " - Run 'reshape complete' once your application has been updated and the previous schema is no longer in use"

265+ " - Run 'reshape migration complete' once your application has been updated and the previous schema is no longer in use"

263 );

266 );

264 Ok(())

267 Ok(())

265}

268}

@@ -281,7 +284,7 @@ fn complete(db: &mut DbConn, state: &mut State) -> anyhow::Result<()> {

281 current_action_index

284 current_action_index

282 } => (migrations, current_migration_index, current_action_index),

285 } => (migrations, current_migration_index, current_action_index),

283 State::Aborting { .. } => {

286 State::Aborting { .. } => {

284− return Err(anyhow!("migration been aborted and can't be completed. Please finish using `reshape abort`."))

287+ return Err(anyhow!("migration been aborted and can't be completed. Please finish using `reshape migration abort`."))

285 }

288 }

286 State::Applying { .. } => {

289 State::Applying { .. } => {

287 return Err(anyhow!("a previous migration unexpectedly failed. Please run `reshape migrate` to try applying the migration again."))

290 return Err(anyhow!("a previous migration unexpectedly failed. Please run `reshape migrate` to try applying the migration again."))

@@ -318,7 +321,8 @@ fn complete(db: &mut DbConn, state: &mut State) -> anyhow::Result<()> {

318 let description = action.describe();

321 let description = action.describe();

319 print!(" + {} ", description);

322 print!(" + {} ", description);

320

323

324+ let ctx =

321− let ctx = MigrationContext::new(migration_index, action_index);

325+ MigrationContext::new(migration_index, action_index, state::current_migration(db)?);

322

326

323 // Update state to indicate that this action has been completed.

327 // Update state to indicate that this action has been completed.

324 // We won't save this new state until after the action has completed.

328 // We won't save this new state until after the action has completed.

@@ -409,7 +413,7 @@ fn abort(db: &mut DbConn, state: &mut State) -> anyhow::Result<()> {

409 last_action_index,

413 last_action_index,

410 } => (migrations, last_migration_index, last_action_index),

414 } => (migrations, last_migration_index, last_action_index),

411 State::Completing { .. } => {

415 State::Completing { .. } => {

412− return Err(anyhow!("Migration completion has already been started. Please run `reshape complete` again to finish it."));

416+ return Err(anyhow!("migration completion has already been started. Please run `reshape migration complete` again to finish it."));

413 }

417 }

414 State::Idle => {

418 State::Idle => {

415 println!("No migration is in progress");

419 println!("No migration is in progress");

@@ -443,7 +447,8 @@ fn abort(db: &mut DbConn, state: &mut State) -> anyhow::Result<()> {

443 continue;

447 continue;

444 }

448 }

445

449

450+ let ctx =

446− let ctx = MigrationContext::new(migration_index, action_index);

451+ MigrationContext::new(migration_index, action_index, state::current_migration(db)?);

447 action

452 action

448 .abort(&ctx, db)

453 .abort(&ctx, db)

449 .with_context(|| format!("failed to abort migration {}", migration.name))

454 .with_context(|| format!("failed to abort migration {}", migration.name))

src/main.rs+12−2

@@ -4,6 +4,7 @@ use std::{

4 path::Path,

5};

7+use anyhow::Context;

7use clap::{Args, Parser};

8use clap::{Args, Parser};

8use reshape::{

9use reshape::{

9 migrations::{Action, Migration},

10 migrations::{Action, Migration},

@@ -195,7 +196,13 @@ fn find_migrations(opts: &FindMigrationsOptions) -> anyhow::Result<Vec<Migration

195 }

196 }

196

197

197 // Sort all files by their file names (without extension)

198 // Sort all files by their file names (without extension)

198− file_paths.sort_unstable_by_key(|path| path.as_path().file_stem().unwrap().to_os_string());

199+ // The files are sorted naturally, e.g. "1_test_migration" < "10_test_migration"

200+ file_paths.sort_unstable_by(|path1, path2| {

201+ let file1 = path1.as_path().file_stem().unwrap().to_str().unwrap();

202+ let file2 = path2.as_path().file_stem().unwrap().to_str().unwrap();

203+

204+ lexical_sort::natural_cmp(file1, file2)

205+ });

199

206

200 file_paths

207 file_paths

201 .iter()

208 .iter()

@@ -211,7 +218,10 @@ fn find_migrations(opts: &FindMigrationsOptions) -> anyhow::Result<Vec<Migration

211 .map(|result| {

218 .map(|result| {

212 result.and_then(|(path, data)| {

219 result.and_then(|(path, data)| {

213 let extension = path.extension().and_then(|ext| ext.to_str()).unwrap();

220 let extension = path.extension().and_then(|ext| ext.to_str()).unwrap();

221+ let file_migration =

214− let file_migration = decode_migration_file(&data, extension)?;

222+ decode_migration_file(&data, extension).with_context(|| {

223+ format!("failed to parse migration file {}", path.display())

224+ })?;

215

225

216 let file_name = path.file_stem().and_then(|name| name.to_str()).unwrap();

226 let file_name = path.file_stem().and_then(|name| name.to_str()).unwrap();

217 Ok(Migration {

227 Ok(Migration {

src/migrations/add_column.rs+214−58

@@ -3,14 +3,25 @@ use crate::{

3 db::{Conn, Transaction},

4 schema::Schema,

5};

6−use anyhow::Context;

6+use anyhow::{bail, Context};

7use serde::{Deserialize, Serialize};

9#[derive(Serialize, Deserialize, Debug)]

10pub struct AddColumn {

11 pub table: String,

12− pub up: Option<String>,

13 pub column: Column,

12 pub column: Column,

13+ pub up: Option<Transformation>,

14+}

15+

16+#[derive(Serialize, Deserialize, Debug)]

17+#[serde(untagged)]

18+pub enum Transformation {

19+ Simple(String),

20+ Update {

21+ table: String,

22+ value: String,

23+ r#where: String,

24+ },

14}

25}

16impl AddColumn {

27impl AddColumn {

@@ -32,6 +43,15 @@ impl AddColumn {

32 )

43 )

33 }

44 }

46+ fn reverse_trigger_name(&self, ctx: &MigrationContext) -> String {

47+ format!(

48+ "{}_add_column_{}_{}_rev",

49+ ctx.prefix(),

50+ self.table,

51+ self.column.name

52+ )

53+ }

54+

35 fn not_null_constraint_name(&self, ctx: &MigrationContext) -> String {

55 fn not_null_constraint_name(&self, ctx: &MigrationContext) -> String {

36 format!(

56 format!(

37 "{}_add_column_not_null_{}_{}",

57 "{}_add_column_not_null_{}_{}",

@@ -61,7 +81,7 @@ impl Action for AddColumn {

61 let temp_column_name = self.temp_column_name(ctx);

81 let temp_column_name = self.temp_column_name(ctx);

63 let mut definition_parts = vec![

83 let mut definition_parts = vec![

64− temp_column_name.to_string(),

84+ format!("\"{}\"", temp_column_name.to_string()),

65 self.column.data_type.to_string(),

85 self.column.data_type.to_string(),

66 ];

86 ];

@@ -86,53 +106,189 @@ impl Action for AddColumn {

86 );

106 );

87 db.run(&query).context("failed to add column")?;

107 db.run(&query).context("failed to add column")?;

108

109+ let declarations: Vec<String> = table

110+ .columns

111+ .iter()

112+ .map(|column| {

113+ format!(

114+ "\"{alias}\" public.{table}.{real_name}%TYPE := NEW.{real_name};",

115+ table = table.real_name,

116+ alias = column.name,

117+ real_name = column.real_name,

118+ )

119+ })

120+ .collect();

121+

89 if let Some(up) = &self.up {

122 if let Some(up) = &self.up {

90− let declarations: Vec<String> = table

123+ if let Transformation::Simple(up) = up {

91− .columns

92− .iter()

93− .map(|column| {

94− format!(

95− "{alias} public.{table}.{real_name}%TYPE := NEW.{real_name};",

96− table = table.real_name,

97− alias = column.name,

98− real_name = column.real_name,

99− )

100− })

101− .collect();

102−

103− // Add triggers to fill in values as they are inserted/updated

124+ // Add triggers to fill in values as they are inserted/updated

104− let query = format!(

125+ let query = format!(

105− r#"

126+ r#"

106− CREATE OR REPLACE FUNCTION {trigger_name}()

127+ CREATE OR REPLACE FUNCTION {trigger_name}()

107− RETURNS TRIGGER AS $$

128+ RETURNS TRIGGER AS $$

108− BEGIN

129+ BEGIN

109− IF NOT reshape.is_new_schema() THEN

130+ IF NOT reshape.is_new_schema() THEN

110− DECLARE

131+ DECLARE

111− {declarations}

132+ {declarations}

112− BEGIN

133+ BEGIN

113− NEW.{temp_column_name} = {up};

134+ NEW."{temp_column_name}" = {up};

114− END;

135+ END;

115− END IF;

136+ END IF;

116− RETURN NEW;

137+ RETURN NEW;

117− END

138+ END

118− $$ language 'plpgsql';

139+ $$ language 'plpgsql';

119−

140+

120− DROP TRIGGER IF EXISTS "{trigger_name}" ON "{table}";

141+ DROP TRIGGER IF EXISTS "{trigger_name}" ON "{table}";

121− CREATE TRIGGER "{trigger_name}" BEFORE UPDATE OR INSERT ON "{table}" FOR EACH ROW EXECUTE PROCEDURE {trigger_name}();

142+ CREATE TRIGGER "{trigger_name}" BEFORE UPDATE OR INSERT ON "{table}" FOR EACH ROW EXECUTE PROCEDURE {trigger_name}();

122− "#,

143+ "#,

123− temp_column_name = temp_column_name,

144+ temp_column_name = temp_column_name,

124− trigger_name = self.trigger_name(ctx),

145+ trigger_name = self.trigger_name(ctx),

125− up = up,

146+ up = up,

126− table = self.table,

147+ table = self.table,

127− declarations = declarations.join("\n"),

148+ declarations = declarations.join("\n"),

128− );

149+ );

129− db.run(&query).context("failed to create up trigger")?;

150+ db.run(&query).context("failed to create up trigger")?;

130− }

131

151

132− // Backfill values in batches

152+ // Backfill values in batches

133− if self.up.is_some() {

153+ common::batch_touch_rows(db, &table.real_name, Some(&temp_column_name))

154+ .context("failed to batch update existing rows")?;

155+ }

156+

157+ if let Transformation::Update {

158+ table: from_table,

159+ value,

160+ r#where,

161+ } = up

162+ {

163+ let existing_schema_name = match &ctx.existing_schema_name {

164+ Some(name) => name,

165+ None => bail!("can't use update without previous migration"),

166+ };

167+

168+ let from_table = schema.get_table(db, &from_table)?;

169+

170+ let from_table_assignments: Vec<String> = from_table

171+ .columns

172+ .iter()

173+ .map(|column| {

174+ format!(

175+ "{table}.{alias} = NEW.{real_name};",

176+ table = from_table.name,

177+ alias = column.name,

178+ real_name = column.real_name,

179+ )

180+ })

181+ .collect();

182+

183+ // Add triggers to fill in values as they are inserted/updated

184+ let query = format!(

185+ r#"

186+ CREATE OR REPLACE FUNCTION {trigger_name}()

187+ RETURNS TRIGGER AS $$

188+ #variable_conflict use_variable

189+ BEGIN

190+ IF NOT reshape.is_new_schema() THEN

191+ DECLARE

192+ {from_table} migration_{existing_schema_name}.{from_table}%ROWTYPE;

193+ BEGIN

194+ {assignments}

195+

196+ -- Don't trigger reverse trigger when making this update

197+ perform set_config('reshape.disable_triggers', 'TRUE', TRUE);

198+

199+ UPDATE public."{changed_table_real}"

200+ SET "{temp_column_name}" = {value}

201+ WHERE {where};

202+

203+ perform set_config('reshape.disable_triggers', '', TRUE);

204+ END;

205+ END IF;

206+ RETURN NEW;

207+ END

208+ $$ language 'plpgsql';

209+

210+ DROP TRIGGER IF EXISTS "{trigger_name}" ON "{from_table_real}";

211+ CREATE TRIGGER "{trigger_name}" BEFORE UPDATE OR INSERT ON "{from_table_real}" FOR EACH ROW EXECUTE PROCEDURE {trigger_name}();

212+ "#,

213+ assignments = from_table_assignments.join("\n"),

214+ changed_table_real = table.real_name,

215+ from_table = from_table.name,

216+ from_table_real = from_table.real_name,

217+ trigger_name = self.trigger_name(ctx),

218+ // declarations = from_table_declarations.join("\n"),

219+ temp_column_name = temp_column_name,

220+ );

221+ db.run(&query).context("failed to create up trigger")?;

222+

223+ let from_table_columns = from_table

224+ .columns

225+ .iter()

226+ .map(|column| format!("{} as {}", column.real_name, column.name))

227+ .collect::<Vec<String>>()

228+ .join(", ");

229+

230+ let changed_table_assignments: Vec<String> = table

231+ .columns

232+ .iter()

233+ .map(|column| {

234+ format!(

235+ "{table}.{alias} := NEW.{real_name};",

236+ table = table.name,

237+ alias = column.name,

238+ real_name = column.real_name,

239+ )

240+ })

241+ .collect();

242+

243+ // Add triggers to fill in values as they are inserted/updated

244+ let query = format!(

245+ r#"

246+ CREATE OR REPLACE FUNCTION {trigger_name}()

247+ RETURNS TRIGGER AS $$

248+ #variable_conflict use_variable

249+ BEGIN

250+ IF NOT reshape.is_new_schema() AND NOT current_setting('reshape.disable_triggers', TRUE) = 'TRUE' THEN

251+ DECLARE

252+ {changed_table} migration_{existing_schema_name}.{changed_table}%ROWTYPE;

253+ __temp_row migration_{existing_schema_name}.{from_table}%ROWTYPE;

254+ BEGIN

255+ {changed_table_assignments}

256+

257+ SELECT {from_table_columns}

258+ INTO __temp_row

259+ FROM migration_{existing_schema_name}.{from_table} {from_table}

260+ WHERE {where};

261+

262+ DECLARE

263+ {from_table} migration_{existing_schema_name}.{from_table}%ROWTYPE;

264+ BEGIN

265+ {from_table} = __temp_row;

266+ NEW.{temp_column_name} = {value};

267+ END;

268+ END;

269+ END IF;

270+ RETURN NEW;

271+ END

272+ $$ language 'plpgsql';

273+

274+ DROP TRIGGER IF EXISTS "{trigger_name}" ON "{changed_table_real}";

275+ CREATE TRIGGER "{trigger_name}" BEFORE UPDATE OR INSERT ON "{changed_table_real}" FOR EACH ROW EXECUTE PROCEDURE {trigger_name}();

276+ "#,

277+ changed_table_assignments = changed_table_assignments.join("\n"),

278+ changed_table_real = table.real_name,

279+ changed_table = table.name,

280+ from_table = from_table.name,

281+ trigger_name = self.reverse_trigger_name(ctx),

282+ temp_column_name = temp_column_name,

283+ // declarations = declarations.join("\n"),

284+ );

285+ db.run(&query)

286+ .context("failed to create reverse up trigger")?;

287+

288+ // Backfill values in batches by touching the from table

134− common::batch_touch_rows(db, &table.real_name, &temp_column_name)

289+ common::batch_touch_rows(db, &from_table.real_name, None)

135− .context("failed to batch update existing rows")?;

290+ .context("failed to batch update existing rows")?;

291+ }

136 }

292 }

137

293

138 // Add a temporary NOT NULL constraint if the column shouldn't be nullable.

294 // Add a temporary NOT NULL constraint if the column shouldn't be nullable.

@@ -142,10 +298,10 @@ impl Action for AddColumn {

142 if !self.column.nullable {

298 if !self.column.nullable {

143 let query = format!(

299 let query = format!(

144 r#"

300 r#"

145− ALTER TABLE "{table}"

301+ ALTER TABLE "{table}"

146− ADD CONSTRAINT "{constraint_name}"

302+ ADD CONSTRAINT "{constraint_name}"

147− CHECK ("{column}" IS NOT NULL) NOT VALID

303+ CHECK ("{column}" IS NOT NULL) NOT VALID

148− "#,

304+ "#,

149 table = self.table,

305 table = self.table,

150 constraint_name = self.not_null_constraint_name(ctx),

306 constraint_name = self.not_null_constraint_name(ctx),

151 column = temp_column_name,

307 column = temp_column_name,

@@ -167,11 +323,11 @@ impl Action for AddColumn {

167 // Remove triggers and procedures

323 // Remove triggers and procedures

168 let query = format!(

324 let query = format!(

169 r#"

325 r#"

170− DROP TRIGGER IF EXISTS "{trigger_name}" ON "{table}";

326+ DROP FUNCTION IF EXISTS "{trigger_name}" CASCADE;

171− DROP FUNCTION IF EXISTS "{trigger_name}";

327+ DROP FUNCTION IF EXISTS "{reverse_trigger_name}" CASCADE;

172 "#,

328 "#,

173− table = self.table,

174 trigger_name = self.trigger_name(ctx),

329 trigger_name = self.trigger_name(ctx),

330+ reverse_trigger_name = self.reverse_trigger_name(ctx),

175 );

331 );

176 transaction

332 transaction

177 .run(&query)

333 .run(&query)

@@ -262,11 +418,11 @@ impl Action for AddColumn {

262 // Remove triggers and procedures

418 // Remove triggers and procedures

263 let query = format!(

419 let query = format!(

264 r#"

420 r#"

265− DROP TRIGGER IF EXISTS "{trigger_name}" ON "{table}";

421+ DROP FUNCTION IF EXISTS "{trigger_name}" CASCADE;

266− DROP FUNCTION IF EXISTS "{trigger_name}";

422+ DROP FUNCTION IF EXISTS "{reverse_trigger_name}" CASCADE;

267 "#,

423 "#,

268− table = self.table,

269 trigger_name = self.trigger_name(ctx),

424 trigger_name = self.trigger_name(ctx),

425+ reverse_trigger_name = self.reverse_trigger_name(ctx),

270 );

426 );

271 db.run(&query).context("failed to drop up trigger")?;

427 db.run(&query).context("failed to drop up trigger")?;

272

428

src/migrations/add_foreign_key.rs+1−1

@@ -48,7 +48,7 @@ impl Action for AddForeignKey {

48 ALTER TABLE "{table}"

49 ADD CONSTRAINT {constraint_name}

50 FOREIGN KEY ({columns})

51− REFERENCES {referenced_table} ({referenced_columns})

51+ REFERENCES "{referenced_table}" ({referenced_columns})

52 NOT VALID

53 "#,

54 table = table.real_name,

src/migrations/alter_column.rs+1−1

@@ -150,7 +150,7 @@ impl Action for AlterColumn {

150 .context("failed to create up and down triggers")?;

151

152 // Backfill values in batches by touching the previous column

153− common::batch_touch_rows(db, &table.real_name, &column.real_name)

153+ common::batch_touch_rows(db, &table.real_name, Some(&column.real_name))

154 .context("failed to batch update existing rows")?;

155

156 // Duplicate any indices to the temporary column

src/migrations/common.rs+14−9

@@ -69,7 +69,11 @@ impl ToSql for PostgresRawValue {

69 postgres::types::to_sql_checked!();

70}

72−pub fn batch_touch_rows(db: &mut dyn Conn, table: &str, column: &str) -> anyhow::Result<()> {

72+pub fn batch_touch_rows(

73+ db: &mut dyn Conn,

74+ table: &str,

75+ column: Option<&str>,

76+) -> anyhow::Result<()> {

73 const BATCH_SIZE: u16 = 1000;

77 const BATCH_SIZE: u16 = 1000;

75 let mut cursor: Option<PostgresRawValue> = None;

79 let mut cursor: Option<PostgresRawValue> = None;

@@ -78,6 +82,13 @@ pub fn batch_touch_rows(db: &mut dyn Conn, table: &str, column: &str) -> anyhow:

78 let mut params: Vec<&(dyn ToSql + Sync)> = Vec::new();

82 let mut params: Vec<&(dyn ToSql + Sync)> = Vec::new();

80 let primary_key = get_primary_key_columns_for_table(db, table)?;

84 let primary_key = get_primary_key_columns_for_table(db, table)?;

85+

86+ // If no column to touch is passed, we default to the first primary key column (just to make some "update")

87+ let touched_column = match column {

88+ Some(column) => column,

89+ None => primary_key.first().unwrap(),

90+ };

91+

81 let primary_key_columns = primary_key.join(", ");

92 let primary_key_columns = primary_key.join(", ");

83 let primary_key_where = primary_key

94 let primary_key_where = primary_key

@@ -120,8 +131,8 @@ pub fn batch_touch_rows(db: &mut dyn Conn, table: &str, column: &str) -> anyhow:

120 ORDER BY {primary_key_columns}

131 ORDER BY {primary_key_columns}

121 LIMIT {batch_size}

132 LIMIT {batch_size}

122 ), update AS (

133 ), update AS (

123− UPDATE public."{table}"

134+ UPDATE public."{table}" "{table}"

124− SET "{column}" = "{column}"

135+ SET "{touched_column}" = "{table}"."{touched_column}"

125 FROM rows

136 FROM rows

126 WHERE {primary_key_where}

137 WHERE {primary_key_where}

127 RETURNING {returning_columns}

138 RETURNING {returning_columns}

@@ -130,13 +141,7 @@ pub fn batch_touch_rows(db: &mut dyn Conn, table: &str, column: &str) -> anyhow:

130 FROM update

141 FROM update

131 LIMIT 1

142 LIMIT 1

132 "#,

143 "#,

133− table = table,

134− primary_key_columns = primary_key_columns,

135− cursor_where = cursor_where,

136 batch_size = BATCH_SIZE,

144 batch_size = BATCH_SIZE,

137− column = column,

138− primary_key_where = primary_key_where,

139− returning_columns = returning_columns,

140 );

145 );

141 let last_value = db

146 let last_value = db

142 .query_with_params(&query, &params)?

147 .query_with_params(&query, &params)?

src/migrations/create_table.rs+122−9

@@ -1,6 +1,9 @@

1+use std::collections::HashMap;

1use super::{common::ForeignKey, Action, Column, MigrationContext};

3use super::{common::ForeignKey, Action, Column, MigrationContext};

2use crate::{

4use crate::{

3 db::{Conn, Transaction},

5 db::{Conn, Transaction},

6+ migrations::common,

4 schema::Schema,

7 schema::Schema,

5};

8};

6use anyhow::Context;

9use anyhow::Context;

@@ -14,6 +17,21 @@ pub struct CreateTable {

15 #[serde(default)]

18 #[serde(default)]

16 pub foreign_keys: Vec<ForeignKey>,

19 pub foreign_keys: Vec<ForeignKey>,

20+

21+ pub up: Option<Transformation>,

22+}

23+

24+#[derive(Serialize, Deserialize, Debug)]

25+pub struct Transformation {

26+ table: String,

27+ values: HashMap<String, String>,

28+ upsert_constraint: Option<String>,

29+}

30+

31+impl CreateTable {

32+ fn trigger_name(&self, ctx: &MigrationContext) -> String {

33+ format!("{}_create_table_{}", ctx.prefix(), self.name)

34+ }

17}

35}

19#[typetag::serde(name = "create_table")]

37#[typetag::serde(name = "create_table")]

@@ -24,7 +42,7 @@ impl Action for CreateTable {

25 fn run(

43 fn run(

26 &self,

44 &self,

27− _ctx: &MigrationContext,

45+ ctx: &MigrationContext,

28 db: &mut dyn Conn,

46 db: &mut dyn Conn,

29 schema: &Schema,

47 schema: &Schema,

30 ) -> anyhow::Result<()> {

48 ) -> anyhow::Result<()> {

@@ -85,7 +103,7 @@ impl Action for CreateTable {

85 ));

103 ));

86 }

104 }

105

88− db.run(&format!(

106+ let query = &format!(

89 r#"

107 r#"

90 CREATE TABLE "{name}" (

108 CREATE TABLE "{name}" (

91 {definition}

109 {definition}

@@ -93,26 +111,121 @@ impl Action for CreateTable {

93 "#,

111 "#,

94 name = self.name,

112 name = self.name,

95 definition = definition_rows.join(",\n"),

113 definition = definition_rows.join(",\n"),

96− ))

114+ );

115+ db.run(query).context("failed to create table")?;

116+

117+ if let Some(Transformation {

118+ table: from_table,

119+ values,

120+ upsert_constraint,

121+ }) = &self.up

122+ {

123+ let from_table = schema.get_table(db, &from_table)?;

124+

125+ let declarations: Vec<String> = from_table

126+ .columns

127+ .iter()

128+ .map(|column| {

129+ format!(

130+ "{alias} public.{table}.{real_name}%TYPE := NEW.{real_name};",

131+ table = from_table.real_name,

132+ alias = column.name,

133+ real_name = column.real_name,

134+ )

135+ })

136+ .collect();

137+

138+ let (insert_columns, insert_values): (Vec<&str>, Vec<&str>) = values

139+ .iter()

140+ .map(|(k, v)| -> (&str, &str) { (k, v) }) // Force &String to &str

141+ .unzip();

142+

143+ let update_set: Vec<String> = values

144+ .iter()

145+ .map(|(field, value)| format!("\"{field}\" = {value}"))

146+ .collect();

147+

148+ // Constraint to check for conflicts. Defaults to the primary key constraint.

149+ let conflict_constraint_name = match upsert_constraint {

150+ Some(custom_constraint) => custom_constraint.clone(),

151+ _ => format!("{table}_pkey", table = self.name),

152+ };

153+

154+ // Add triggers to fill in values as they are inserted/updated

155+ let query = format!(

156+ r#"

157+ CREATE OR REPLACE FUNCTION {trigger_name}()

158+ RETURNS TRIGGER AS $$

159+ #variable_conflict use_variable

160+ BEGIN

161+ IF NOT reshape.is_new_schema() THEN

162+ DECLARE

163+ {declarations}

164+ BEGIN

165+ INSERT INTO public."{changed_table_real}" ({columns})

166+ VALUES ({values})

167+ ON CONFLICT ON CONSTRAINT "{conflict_constraint_name}"

168+ DO UPDATE SET

169+ {updates};

170+ END;

171+ END IF;

172+ RETURN NEW;

173+ END

174+ $$ language 'plpgsql';

175+

176+ DROP TRIGGER IF EXISTS "{trigger_name}" ON "{from_table_real}";

177+ CREATE TRIGGER "{trigger_name}" BEFORE UPDATE OR INSERT ON "{from_table_real}" FOR EACH ROW EXECUTE PROCEDURE {trigger_name}();

178+ "#,

179+ changed_table_real = self.name,

180+ from_table_real = from_table.real_name,

181+ trigger_name = self.trigger_name(ctx),

182+ declarations = declarations.join("\n"),

183+ columns = insert_columns.join(", "),

184+ values = insert_values.join(", "),

185+ updates = update_set.join(",\n"),

186+ );

97− .context("failed to create table")?;

187+ db.run(&query).context("failed to create up trigger")?;

188+

189+ // Backfill values in batches by touching the from table

190+ common::batch_touch_rows(db, &from_table.real_name, None)

191+ .context("failed to batch update existing rows")?;

192+ }

193+

98 Ok(())

194 Ok(())

99 }

195 }

100

196

101 fn complete<'a>(

197 fn complete<'a>(

102 &self,

198 &self,

103− _ctx: &MigrationContext,

199+ ctx: &MigrationContext,

104− _db: &'a mut dyn Conn,

200+ db: &'a mut dyn Conn,

105 ) -> anyhow::Result<Option<Transaction<'a>>> {

201 ) -> anyhow::Result<Option<Transaction<'a>>> {

106− // Do nothing

202+ // Remove triggers and procedures

203+ let query = format!(

204+ r#"

205+ DROP FUNCTION IF EXISTS "{trigger_name}" CASCADE;

206+ "#,

207+ trigger_name = self.trigger_name(ctx),

208+ );

209+ db.run(&query).context("failed to drop up trigger")?;

210+

107 Ok(None)

211 Ok(None)

108 }

212 }

109

213

110 fn update_schema(&self, _ctx: &MigrationContext, _schema: &mut Schema) {}

214 fn update_schema(&self, _ctx: &MigrationContext, _schema: &mut Schema) {}

111

215

112− fn abort(&self, _ctx: &MigrationContext, db: &mut dyn Conn) -> anyhow::Result<()> {

216+ fn abort(&self, ctx: &MigrationContext, db: &mut dyn Conn) -> anyhow::Result<()> {

217+ // Remove triggers and procedures

218+ let query = format!(

219+ r#"

220+ DROP FUNCTION IF EXISTS "{trigger_name}" CASCADE;

221+ "#,

222+ trigger_name = self.trigger_name(ctx),

223+ );

224+ db.run(&query).context("failed to drop up trigger")?;

225+

113 db.run(&format!(

226 db.run(&format!(

114 r#"

227 r#"

115− DROP TABLE IF EXISTS {name}

228+ DROP TABLE IF EXISTS "{name}"

116 "#,

229 "#,

117 name = self.name,

230 name = self.name,

118 ))

231 ))

src/migrations/mod.rs+7−1

@@ -88,13 +88,19 @@ impl Clone for Migration {

88pub struct MigrationContext {

89 migration_index: usize,

90 action_index: usize,

91+ existing_schema_name: Option<String>,

91}

92}

93impl MigrationContext {

94impl MigrationContext {

95+ pub fn new(

94− pub fn new(migration_index: usize, action_index: usize) -> Self {

96+ migration_index: usize,

97+ action_index: usize,

98+ existing_schema_name: Option<String>,

99+ ) -> Self {

95 MigrationContext {

100 MigrationContext {

96 migration_index,

101 migration_index,

97 action_index,

102 action_index,

103+ existing_schema_name,

98 }

104 }

99 }

105 }

100

106

src/migrations/remove_column.rs+339−34

@@ -3,14 +3,25 @@ use crate::{

3 db::{Conn, Transaction},

4 schema::Schema,

5};

6−use anyhow::Context;

6+use anyhow::{anyhow, bail, Context};

7use serde::{Deserialize, Serialize};

9#[derive(Serialize, Deserialize, Debug)]

10pub struct RemoveColumn {

11 pub table: String,

12 pub column: String,

13− pub down: Option<String>,

13+ pub down: Option<Transformation>,

14+}

15+

16+#[derive(Serialize, Deserialize, Debug)]

17+#[serde(untagged)]

18+pub enum Transformation {

19+ Simple(String),

20+ Update {

21+ table: String,

22+ value: String,

23+ r#where: String,

24+ },

14}

25}

16impl RemoveColumn {

27impl RemoveColumn {

@@ -22,6 +33,33 @@ impl RemoveColumn {

22 self.column

33 self.column

23 )

34 )

24 }

35 }

36+

37+ fn reverse_trigger_name(&self, ctx: &MigrationContext) -> String {

38+ format!(

39+ "{}_remove_column_{}_{}_rev",

40+ ctx.prefix(),

41+ self.table,

42+ self.column

43+ )

44+ }

45+

46+ fn not_null_constraint_trigger_name(&self, ctx: &MigrationContext) -> String {

47+ format!(

48+ "{}_remove_column_{}_{}_nn",

49+ ctx.prefix(),

50+ self.table,

51+ self.column

52+ )

53+ }

54+

55+ fn not_null_constraint_name(&self, ctx: &MigrationContext) -> String {

56+ format!(

57+ "{}_add_column_not_null_{}_{}",

58+ ctx.prefix(),

59+ self.table,

60+ self.column

61+ )

62+ }

25}

63}

27#[typetag::serde(name = "remove_column")]

65#[typetag::serde(name = "remove_column")]

@@ -39,10 +77,13 @@ impl Action for RemoveColumn {

39 db: &mut dyn Conn,

77 db: &mut dyn Conn,

40 schema: &Schema,

78 schema: &Schema,

41 ) -> anyhow::Result<()> {

79 ) -> anyhow::Result<()> {

80+ let table = schema.get_table(db, &self.table)?;

81+ let column = table

82+ .get_column(&self.column)

83+ .ok_or_else(|| anyhow!("no such column {} exists", self.column))?;

84+

42 // Add down trigger

85 // Add down trigger

43 if let Some(down) = &self.down {

86 if let Some(down) = &self.down {

44− let table = schema.get_table(db, &self.table)?;

45−

46 let declarations: Vec<String> = table

87 let declarations: Vec<String> = table

47 .columns

88 .columns

48 .iter()

89 .iter()

@@ -56,32 +97,226 @@ impl Action for RemoveColumn {

56 })

97 })

57 .collect();

98 .collect();

100+ if let Transformation::Simple(down) = down {

59− let query = format!(

101+ let query = format!(

60− r#"

102+ r#"

61− CREATE OR REPLACE FUNCTION {trigger_name}()

103+ CREATE OR REPLACE FUNCTION {trigger_name}()

62− RETURNS TRIGGER AS $$

104+ RETURNS TRIGGER AS $$

63− BEGIN

105+ BEGIN

64− IF reshape.is_new_schema() THEN

106+ IF reshape.is_new_schema() THEN

65− DECLARE

107+ DECLARE

108+ {declarations}

109+ BEGIN

110+ NEW.{column_name} = {down};

111+ END;

112+ END IF;

113+ RETURN NEW;

114+ END

115+ $$ language 'plpgsql';

116+

117+ DROP TRIGGER IF EXISTS "{trigger_name}" ON "{table}";

118+ CREATE TRIGGER "{trigger_name}" BEFORE UPDATE OR INSERT ON "{table}" FOR EACH ROW EXECUTE PROCEDURE {trigger_name}();

119+ "#,

120+ column_name = self.column,

121+ trigger_name = self.trigger_name(ctx),

122+ down = down,

123+ table = self.table,

66− {declarations}

124+ declarations = declarations.join("\n"),

125+ );

126+ db.run(&query).context("failed to create down trigger")?;

127+ }

128+

129+ if let Transformation::Update {

130+ table: from_table,

131+ value,

132+ r#where,

133+ } = down

134+ {

135+ let existing_schema_name = match &ctx.existing_schema_name {

136+ Some(name) => name,

137+ None => bail!("can't use update without previous migration"),

138+ };

139+

140+ let from_table = schema.get_table(db, &from_table)?;

141+

142+ let maybe_null_check = if !column.nullable {

143+ // Replace NOT NULL constraint with a constraint trigger that only triggers on the old schema.

144+ // We will add a null check to the down function on the new schema below as well to cover both cases.

145+ // As we are using a complex down function, we must remove the NOT NULL check for the new schema.

146+ // NOT NULL is not checked at the end of a transaction, but immediately upon update.

147+ let query = format!(

148+ r#"

149+ CREATE OR REPLACE FUNCTION {trigger_name}()

150+ RETURNS TRIGGER AS $$

67 BEGIN

151 BEGIN

68− NEW.{column_name} = {down};

152+ IF NOT reshape.is_new_schema() THEN

153+ IF NEW.{column} IS NULL THEN

154+ RAISE EXCEPTION '{column} can not be null';

69− END;

155+ END IF;

70− END IF;

156+ END IF;

71− RETURN NEW;

157+ RETURN NEW;

72− END

158+ END

73− $$ language 'plpgsql';

159+ $$ language 'plpgsql';

74−

160+

75− DROP TRIGGER IF EXISTS "{trigger_name}" ON "{table}";

161+ DROP TRIGGER IF EXISTS "{trigger_name}" ON "{table}";

162+

163+ CREATE CONSTRAINT TRIGGER "{trigger_name}"

164+ AFTER INSERT OR UPDATE

165+ ON "{table}"

166+ FOR EACH ROW

76− CREATE TRIGGER "{trigger_name}" BEFORE UPDATE OR INSERT ON "{table}" FOR EACH ROW EXECUTE PROCEDURE {trigger_name}();

167+ EXECUTE PROCEDURE {trigger_name}();

77− "#,

168+ "#,

78− column_name = self.column,

169+ table = self.table,

79− trigger_name = self.trigger_name(ctx),

170+ trigger_name = self.not_null_constraint_trigger_name(ctx),

80− down = down,

171+ column = self.column,

172+ );

173+ db.run(&query)

174+ .context("failed to create null constraint trigger")?;

175+

176+ db.run(&format!(

177+ r#"

178+ ALTER TABLE {table}

179+ ALTER COLUMN {column}

180+ DROP NOT NULL

181+ "#,

81− table = self.table,

182+ table = self.table,

183+ column = self.column

184+ ))

185+ .context("failed to remove column not null constraint")?;

186+

187+ format!(

188+ r#"

189+ IF {value} IS NULL THEN

190+ RAISE EXCEPTION '{column_name} can not be null';

191+ END IF;

192+ "#,

193+ column_name = self.column,

194+ )

195+ } else {

196+ "".to_string()

197+ };

198+

199+ let into_variables = from_table

200+ .columns

201+ .iter()

202+ .map(|column| {

203+ format!(

204+ "NEW.{real_name} AS {alias}",

205+ alias = column.name,

206+ real_name = column.real_name,

207+ )

208+ })

209+ .collect::<Vec<String>>()

210+ .join(", ");

211+

212+ let query = format!(

213+ r#"

214+ CREATE OR REPLACE FUNCTION {trigger_name}()

215+ RETURNS TRIGGER AS $$

216+ #variable_conflict use_variable

217+ BEGIN

218+ IF reshape.is_new_schema() THEN

219+ DECLARE

220+ {from_table} record;

221+ BEGIN

222+ SELECT {into_variables}

223+ INTO {from_table};

224+

225+ {maybe_null_check}

226+

227+ -- Don't trigger reverse trigger when making this update

228+ perform set_config('reshape.disable_triggers', 'TRUE', TRUE);

229+

230+ UPDATE "migration_{existing_schema_name}"."{changed_table}" "{changed_table}"

231+ SET "{column_name}" = {value}

232+ WHERE {where};

233+

234+ perform set_config('reshape.disable_triggers', '', TRUE);

235+ END;

236+ END IF;

237+ RETURN NEW;

238+ END

239+ $$ language 'plpgsql';

240+

241+ DROP TRIGGER IF EXISTS "{trigger_name}" ON "{from_table_real}";

242+ CREATE TRIGGER "{trigger_name}" BEFORE UPDATE OR INSERT ON "{from_table_real}" FOR EACH ROW EXECUTE PROCEDURE {trigger_name}();

243+ "#,

244+ changed_table = self.table,

245+ from_table = from_table.name,

246+ from_table_real = from_table.real_name,

247+ column_name = self.column,

248+ trigger_name = self.trigger_name(ctx),

249+ );

250+ db.run(&query).context("failed to create down trigger")?;

251+

252+ let changed_into_variables = table

253+ .columns

254+ .iter()

255+ .map(|column| {

256+ format!(

257+ "NEW.{real_name} AS {alias}",

258+ alias = column.name,

259+ real_name = column.real_name,

260+ )

261+ })

262+ .collect::<Vec<String>>()

263+ .join(", ");

264+

265+ let from_table_columns = from_table

266+ .columns

267+ .iter()

268+ .map(|column| format!("{} as {}", column.real_name, column.name))

269+ .collect::<Vec<String>>()

270+ .join(", ");

271+

272+ let query = format!(

273+ r#"

274+ CREATE OR REPLACE FUNCTION {trigger_name}()

275+ RETURNS TRIGGER AS $$

276+ #variable_conflict use_variable

277+ BEGIN

278+ IF reshape.is_new_schema() AND NOT current_setting('reshape.disable_triggers', TRUE) = 'TRUE' THEN

279+ DECLARE

280+ {changed_table} record;

281+ __temp_row record;

282+ BEGIN

283+ SELECT {changed_into_variables}

284+ INTO {changed_table};

285+

286+ SELECT *

287+ INTO __temp_row

288+ FROM (

289+ SELECT {from_table_columns}

290+ FROM public.{from_table_real}

291+ ) {from_table}

292+ WHERE {where};

293+

294+ DECLARE

295+ {from_table} record;

296+ BEGIN

297+ {from_table} := __temp_row;

298+ NEW.{column_name_real} = {value};

299+ END;

300+ END;

301+ END IF;

302+ RETURN NEW;

303+ END

304+ $$ language 'plpgsql';

305+

306+ DROP TRIGGER IF EXISTS "{trigger_name}" ON "{changed_table_real}";

307+ CREATE TRIGGER "{trigger_name}" BEFORE UPDATE OR INSERT ON "{changed_table_real}" FOR EACH ROW EXECUTE PROCEDURE {trigger_name}();

308+ "#,

309+ changed_table = table.name,

310+ changed_table_real = table.real_name,

311+ from_table = from_table.name,

312+ from_table_real = from_table.real_name,

313+ column_name_real = column.real_name,

314+ trigger_name = self.reverse_trigger_name(ctx),

82− declarations = declarations.join("\n"),

315+ // declarations = declarations.join("\n"),

83− );

316+ );

317+ db.run(&query)

84− db.run(&query).context("failed to create down trigger")?;

318+ .context("failed to create reverse down trigger")?;

319+ }

85 }

320 }

321

87 Ok(())

322 Ok(())

@@ -111,12 +346,15 @@ impl Action for RemoveColumn {

111 ALTER TABLE "{table}"

346 ALTER TABLE "{table}"

112 DROP COLUMN IF EXISTS "{column}";

347 DROP COLUMN IF EXISTS "{column}";

113

348

114− DROP TRIGGER IF EXISTS "{trigger_name}" ON "{table}";

349+ DROP FUNCTION IF EXISTS "{trigger_name}" CASCADE;

350+ DROP FUNCTION IF EXISTS "{reverse_trigger_name}" CASCADE;

115− DROP FUNCTION IF EXISTS "{trigger_name}";

351+ DROP FUNCTION IF EXISTS "{null_trigger_name}" CASCADE;

116 "#,

352 "#,

117 table = self.table,

353 table = self.table,

118 column = self.column,

354 column = self.column,

119 trigger_name = self.trigger_name(ctx),

355 trigger_name = self.trigger_name(ctx),

356+ reverse_trigger_name = self.reverse_trigger_name(ctx),

357+ null_trigger_name = self.not_null_constraint_trigger_name(ctx),

120 );

358 );

121 db.run(&query)

359 db.run(&query)

122 .context("failed to drop column and down trigger")?;

360 .context("failed to drop column and down trigger")?;

@@ -133,14 +371,81 @@ impl Action for RemoveColumn {

133 }

371 }

134

372

135 fn abort(&self, ctx: &MigrationContext, db: &mut dyn Conn) -> anyhow::Result<()> {

373 fn abort(&self, ctx: &MigrationContext, db: &mut dyn Conn) -> anyhow::Result<()> {

374+ // We might have temporaily removed the NOT NULL check and have to reinstate it

375+ let has_not_null_function = !db

376+ .query_with_params(

377+ "

378+ SELECT routine_name

379+ FROM information_schema.routines

380+ WHERE routine_schema = 'public'

381+ AND routine_name = $1

382+ ",

383+ &[&self.not_null_constraint_trigger_name(ctx)],

384+ )

385+ .context("failed to get any NOT NULL function")?

386+ .is_empty();

387+

388+ if has_not_null_function {

389+ // Make column NOT NULL again without taking any long lived locks with a temporary constraint

390+ let query = format!(

391+ r#"

392+ ALTER TABLE "{table}"

393+ ADD CONSTRAINT "{constraint_name}"

394+ CHECK ("{column}" IS NOT NULL) NOT VALID

395+ "#,

396+ table = self.table,

397+ constraint_name = self.not_null_constraint_name(ctx),

398+ column = self.column,

399+ );

400+ db.run(&query)

401+ .context("failed to add NOT NULL constraint")?;

402+

403+ let query = format!(

404+ r#"

405+ ALTER TABLE "{table}"

406+ VALIDATE CONSTRAINT "{constraint_name}"

407+ "#,

408+ table = self.table,

409+ constraint_name = self.not_null_constraint_name(ctx),

410+ );

411+ db.run(&query)

412+ .context("failed to validate NOT NULL constraint")?;

413+

414+ // This ALTER TABLE call will not require any exclusive locks as it can use the validated constraint from above

415+ db.run(&format!(

416+ r#"

417+ ALTER TABLE {table}

418+ ALTER COLUMN {column}

419+ SET NOT NULL

420+ "#,

421+ table = self.table,

422+ column = self.column

423+ ))

424+ .context("failed to reinstate column NOT NULL")?;

425+

426+ // Drop the temporary constraint

427+ let query = format!(

428+ r#"

429+ ALTER TABLE "{table}"

430+ DROP CONSTRAINT "{constraint_name}"

431+ "#,

432+ table = self.table,

433+ constraint_name = self.not_null_constraint_name(ctx),

434+ );

435+ db.run(&query)

436+ .context("failed to drop NOT NULL constraint")?;

437+ }

438+

136 // Remove function and trigger

439 // Remove function and trigger

137 db.run(&format!(

440 db.run(&format!(

138 r#"

441 r#"

139− DROP TRIGGER IF EXISTS "{trigger_name}" ON "{table}";

442+ DROP FUNCTION IF EXISTS "{trigger_name}" CASCADE;

443+ DROP FUNCTION IF EXISTS "{reverse_trigger_name}" CASCADE;

140− DROP FUNCTION IF EXISTS "{trigger_name}";

444+ DROP FUNCTION IF EXISTS "{null_trigger_name}" CASCADE;

141 "#,

445 "#,

142− table = self.table,

143 trigger_name = self.trigger_name(ctx),

446 trigger_name = self.trigger_name(ctx),

447+ reverse_trigger_name = self.reverse_trigger_name(ctx),

448+ null_trigger_name = self.not_null_constraint_trigger_name(ctx),

144 ))

449 ))

145 .context("failed to drop down trigger")?;

450 .context("failed to drop down trigger")?;

146

451

src/schema.rs+1−1

@@ -209,7 +209,7 @@ impl Schema {

209 let real_columns: Vec<(String, String, bool, Option<String>)> = db

210 .query(&format!(

211 "

212− SELECT column_name, data_type, is_nullable, column_default

212+ SELECT column_name, CASE WHEN data_type = 'USER-DEFINED' THEN udt_name ELSE data_type END, is_nullable, column_default

213 FROM information_schema.columns

214 WHERE table_name = '{table}' AND table_schema = 'public'

215 ORDER BY ordinal_position

tests/add_column.rs+99

@@ -260,3 +260,102 @@ fn add_column_with_default() {

260

261 test.run();

262}

263+

264+#[test]

265+fn add_column_with_complex_up() {

266+ let mut test = Test::new("Add column complex");

267+

268+ test.first_migration(

269+ r#"

270+ name = "create_tables"

271+

272+ [[actions]]

273+ type = "create_table"

274+ name = "users"

275+ primary_key = ["id"]

276+

277+ [[actions.columns]]

278+ name = "id"

279+ type = "INTEGER"

280+

281+ [[actions.columns]]

282+ name = "email"

283+ type = "TEXT"

284+

285+ [[actions]]

286+ type = "create_table"

287+ name = "profiles"

288+ primary_key = ["user_id"]

289+

290+ [[actions.columns]]

291+ name = "user_id"

292+ type = "INTEGER"

293+ "#,

294+ );

295+

296+ test.second_migration(

297+ r#"

298+ name = "add_profiles_email_column"

299+

300+ [[actions]]

301+ type = "add_column"

302+ table = "profiles"

303+

304+ [actions.column]

305+ name = "email"

306+ type = "TEXT"

307+ nullable = false

308+

309+ [actions.up]

310+ table = "users"

311+ value = "users.email"

312+ where = "profiles.user_id = users.id"

313+ "#,

314+ );

315+

316+ test.after_first(|db| {

317+ db.simple_query("INSERT INTO users (id, email) VALUES (1, 'test@example.com')")

318+ .unwrap();

319+ db.simple_query("INSERT INTO profiles (user_id) VALUES (1)")

320+ .unwrap();

321+ });

322+

323+ test.intermediate(|old_db, new_db| {

324+ // Ensure email was backfilled on profiles

325+ let email: String = new_db

326+ .query(

327+ "

328+ SELECT email

329+ FROM profiles

330+ WHERE user_id = 1

331+ ",

332+ &[],

333+ )

334+ .unwrap()

335+ .first()

336+ .map(|row| row.get("email"))

337+ .unwrap();

338+ assert_eq!("test@example.com", email);

339+

340+ // Ensure email change in old schema is propagated to profiles table in new schema

341+ old_db

342+ .simple_query("UPDATE users SET email = 'test2@example.com' WHERE id = 1")

343+ .unwrap();

344+ let email: String = new_db

345+ .query(

346+ "

347+ SELECT email

348+ FROM profiles

349+ WHERE user_id = 1

350+ ",

351+ &[],

352+ )

353+ .unwrap()

354+ .first()

355+ .map(|row| row.get("email"))

356+ .unwrap();

357+ assert_eq!("test2@example.com", email);

358+ });

359+

360+ test.run();

361+}

tests/complex.rsnew file+379

@@ -0,0 +1,379 @@

1+mod common;

2+use common::Test;

4+#[test]

5+fn move_column_between_tables() {

6+ let mut test = Test::new("Move column between tables");

8+ test.first_migration(

9+ r#"

10+ name = "create_tables"

11+

12+ [[actions]]

13+ type = "create_table"

14+ name = "users"

15+ primary_key = ["id"]

16+

17+ [[actions.columns]]

18+ name = "id"

19+ type = "INTEGER"

20+

21+ [[actions.columns]]

22+ name = "email"

23+ type = "TEXT"

24+

25+ [[actions]]

26+ type = "create_table"

27+ name = "profiles"

28+ primary_key = ["id"]

29+

30+ [[actions.columns]]

31+ name = "id"

32+ type = "INTEGER"

33+

34+ [[actions.columns]]

35+ name = "user_id"

36+ type = "INTEGER"

37+ nullable = false

38+ "#,

39+ );

40+

41+ test.second_migration(

42+ r#"

43+ name = "move_email_column"

44+

45+ [[actions]]

46+ type = "add_column"

47+ table = "profiles"

48+

49+ [actions.column]

50+ name = "email"

51+ type = "TEXT"

52+ nullable = false

53+

54+ # When `users` is updated in the old schema, we write the email value to `profiles`

55+ # When `profiles` is updated in the old schema, the equivalent `users.email` will also be updated

56+ [actions.up]

57+ table = "users"

58+ value = "users.email"

59+ where = "profiles.user_id = users.id"

60+

61+ [[actions]]

62+ type = "remove_column"

63+ table = "users"

64+ column = "email"

65+

66+ # When `profiles` is changed in the new schema, we write the email address back to the removed column

67+ [actions.down]

68+ table = "profiles"

69+ value = "profiles.email"

70+ where = "users.id = profiles.user_id"

71+ "#,

72+ );

73+

74+ test.after_first(|db| {

75+ db.simple_query("INSERT INTO users (id, email) VALUES (1, 'test1@test.com')")

76+ .unwrap();

77+ db.simple_query("INSERT INTO users (id, email) VALUES (2, 'test2@test.com')")

78+ .unwrap();

79+

80+ db.simple_query("INSERT INTO profiles (id, user_id) VALUES (1, 1)")

81+ .unwrap();

82+ db.simple_query("INSERT INTO profiles (id, user_id) VALUES (2, 2)")

83+ .unwrap();

84+ });

85+

86+ test.intermediate(|old_db, new_db| {

87+ // Ensure emails were backfilled into profiles

88+ let profiles_emails: Vec<String> = new_db

89+ .query(

90+ r#"

91+ SELECT email

92+ FROM profiles

93+ ORDER BY id

94+ "#,

95+ &[],

96+ )

97+ .unwrap()

98+ .iter()

99+ .map(|row| row.get("email"))

100+ .collect();

101+ assert_eq!(vec!("test1@test.com", "test2@test.com"), profiles_emails);

102+

103+ // Ensure insert in old schema updates new

104+ old_db

105+ .simple_query("INSERT INTO users (id, email) VALUES (3, 'test3@test.com')")

106+ .unwrap();

107+ old_db

108+ .simple_query("INSERT INTO profiles (id, user_id) VALUES (3, 3)")

109+ .unwrap();

110+ let new_email: String = new_db

111+ .query("SELECT email FROM profiles WHERE id = 3", &[])

112+ .unwrap()

113+ .first()

114+ .map(|row| row.get("email"))

115+ .unwrap();

116+ assert_eq!("test3@test.com", new_email);

117+

118+ // Ensure updates in old schema updates new

119+ old_db

120+ .simple_query("UPDATE users SET email = 'test3+updated@test.com' WHERE id = 3")

121+ .unwrap();

122+ let new_email: String = new_db

123+ .query("SELECT email FROM profiles WHERE id = 3", &[])

124+ .unwrap()

125+ .first()

126+ .map(|row| row.get("email"))

127+ .unwrap();

128+ assert_eq!("test3+updated@test.com", new_email);

129+

130+ // Ensure insert in new schema updates old

131+ new_db

132+ .simple_query(

133+ "INSERT INTO profiles (id, user_id, email) VALUES (4, 4, 'test4@test.com')",

134+ )

135+ .unwrap();

136+ new_db

137+ .simple_query("INSERT INTO users (id) VALUES (4)")

138+ .unwrap();

139+ let old_email: String = old_db

140+ .query("SELECT email FROM users WHERE id = 4", &[])

141+ .unwrap()

142+ .first()

143+ .map(|row| row.get("email"))

144+ .unwrap();

145+ assert_eq!("test4@test.com", old_email);

146+

147+ // Ensure update in new schema updates old

148+ new_db

149+ .simple_query("UPDATE profiles SET email = 'test4+updated@test.com' WHERE id = 4")

150+ .unwrap();

151+ let old_email: String = old_db

152+ .query("SELECT email FROM users WHERE id = 4", &[])

153+ .unwrap()

154+ .first()

155+ .map(|row| row.get("email"))

156+ .unwrap();

157+ assert_eq!("test4+updated@test.com", old_email);

158+ });

159+

160+ test.run();

161+}

162+

163+#[test]

164+fn extract_relation_into_new_table() {

165+ let mut test = Test::new("Extract relation into new table");

166+

167+ test.first_migration(

168+ r#"

169+ name = "create_tables"

170+

171+ [[actions]]

172+ type = "create_table"

173+ name = "accounts"

174+ primary_key = ["id"]

175+

176+ [[actions.columns]]

177+ name = "id"

178+ type = "INTEGER"

179+

180+ [[actions]]

181+ type = "create_table"

182+ name = "users"

183+ primary_key = ["id"]

184+

185+ [[actions.columns]]

186+ name = "id"

187+ type = "INTEGER"

188+

189+ [[actions.columns]]

190+ name = "account_id"

191+ type = "INTEGER"

192+ nullable = false

193+

194+ [[actions.columns]]

195+ name = "account_role"

196+ type = "TEXT"

197+ nullable = false

198+ "#,

199+ );

200+

201+ test.second_migration(

202+ r#"

203+ name = "add_account_user_connection"

204+

205+ [[actions]]

206+ type = "create_table"

207+ name = "user_account_connections"

208+ primary_key = ["account_id", "user_id"]

209+

210+ [[actions.columns]]

211+ name = "account_id"

212+ type = "INTEGER"

213+

214+ [[actions.columns]]

215+ name = "user_id"

216+ type = "INTEGER"

217+

218+ [[actions.columns]]

219+ name = "role"

220+ type = "TEXT"

221+ nullable = false

222+

223+ [actions.up]

224+ table = "users"

225+ values = { user_id = "id", account_id = "account_id", role = "UPPER(account_role)" }

226+ where = "user_account_connections.user_id = users.id"

227+

228+ [[actions]]

229+ type = "remove_column"

230+ table = "users"

231+ column = "account_id"

232+

233+ [actions.down]

234+ table = "user_account_connections"

235+ value = "user_account_connections.account_id"

236+ where = "users.id = user_account_connections.user_id"

237+

238+ [[actions]]

239+ type = "remove_column"

240+ table = "users"

241+ column = "account_role"

242+

243+ [actions.down]

244+ table = "user_account_connections"

245+ value = "LOWER(user_account_connections.role)"

246+ where = "users.id = user_account_connections.user_id"

247+ "#,

248+ );

249+

250+ test.after_first(|db| {

251+ db.simple_query("INSERT INTO accounts (id) VALUES (1)")

252+ .unwrap();

253+ db.simple_query("INSERT INTO users (id, account_id, account_role) VALUES (1, 1, 'admin')")

254+ .unwrap();

255+ });

256+

257+ test.intermediate(|old_db, new_db| {

258+ // Ensure connections was backfilled

259+ let rows: Vec<(i32, i32, String)> = new_db

260+ .query(

261+ "

262+ SELECT account_id, user_id, role

263+ FROM user_account_connections

264+ ",

265+ &[],

266+ )

267+ .unwrap()

268+ .iter()

269+ .map(|row| (row.get("account_id"), row.get("user_id"), row.get("role")))

270+ .collect();

271+ assert_eq!(1, rows.len());

272+

273+ let row = rows.first().unwrap();

274+ assert_eq!(1, row.0);

275+ assert_eq!(1, row.1);

276+ assert_eq!("ADMIN", row.2);

277+

278+ // Ensure inserted user in old schema creates a new connection

279+ old_db

280+ .simple_query(

281+ "INSERT INTO users (id, account_id, account_role) VALUES (2, 1, 'developer')",

282+ )

283+ .unwrap();

284+ assert!(

285+ new_db

286+ .query(

287+ "

288+ SELECT account_id, user_id, role

289+ FROM user_account_connections

290+ WHERE account_id = 1 AND user_id = 2 AND role = 'DEVELOPER'

291+ ",

292+ &[],

293+ )

294+ .unwrap()

295+ .len()

296+ == 1

297+ );

298+

299+ // Ensure NOT NULL constraint still applies to old schema

300+ let result = old_db

301+ .simple_query(

302+ "INSERT INTO users (id, account_id, account_role) VALUES (2, NULL, 'developer')",

303+ );

304+ assert!(result.is_err());

305+

306+ // Ensure updated user role in old schema updates connection in new schema

307+ old_db

308+ .simple_query("UPDATE users SET account_role = 'admin' WHERE id = 2")

309+ .unwrap();

310+ assert!(

311+ new_db

312+ .query(

313+ "

314+ SELECT account_id, user_id, role

315+ FROM user_account_connections

316+ WHERE account_id = 1 AND user_id = 2 AND role = 'ADMIN'

317+ ",

318+ &[],

319+ )

320+ .unwrap()

321+ .len()

322+ == 1

323+ );

324+

325+ // Ensure updated connection in new schema updates old schema user

326+ new_db

327+ .simple_query(

328+ "UPDATE user_account_connections SET role = 'DEVELOPER' WHERE account_id = 1 AND user_id = 2",

329+ )

330+ .unwrap();

331+ assert!(

332+ old_db

333+ .query(

334+ "

335+ SELECT id

336+ FROM users

337+ WHERE id = 2 AND account_id = 1 AND account_role = 'developer'

338+ ",

339+ &[],

340+ )

341+ .unwrap()

342+ .len()

343+ == 1

344+ );

345+

346+ // Ensure insert of user with connection through new schema updates user in old schema

347+ new_db

348+ .simple_query(

349+ r#"

350+ BEGIN;

351+ INSERT INTO users (id) VALUES (3);

352+ INSERT INTO user_account_connections (user_id, account_id, role) VALUES (3, 1, 'DEVELOPER');

353+ COMMIT;

354+ "#,

355+ )

356+ .unwrap();

357+ new_db

358+ .simple_query(

359+ "",

360+ )

361+ .unwrap();

362+ assert!(

363+ old_db

364+ .query(

365+ "

366+ SELECT id

367+ FROM users

368+ WHERE id = 3 AND account_id = 1 AND account_role = 'developer'

369+ ",

370+ &[],

371+ )

372+ .unwrap()

373+ .len()

374+ == 1

375+ );

376+ });

377+

378+ test.run();

379+}

tests/remove_column.rs+86

@@ -128,4 +128,90 @@ fn remove_column_with_index() {

128

129 assert_eq!(0, count, "expected index to not exist");

130 });

131+

132+ test.run();

133+}

134+

135+#[test]

136+fn remove_column_with_complex_down() {

137+ let mut test = Test::new("Remove column complex");

138+

139+ test.first_migration(

140+ r#"

141+ name = "create_tables"

142+

143+ [[actions]]

144+ type = "create_table"

145+ name = "users"

146+ primary_key = ["id"]

147+

148+ [[actions.columns]]

149+ name = "id"

150+ type = "INTEGER"

151+

152+ [[actions.columns]]

153+ name = "email"

154+ type = "TEXT"

155+

156+ [[actions]]

157+ type = "create_table"

158+ name = "profiles"

159+ primary_key = ["user_id"]

160+

161+ [[actions.columns]]

162+ name = "user_id"

163+ type = "INTEGER"

164+

165+ [[actions.columns]]

166+ name = "email"

167+ type = "TEXT"

168+ "#,

169+ );

170+

171+ test.second_migration(

172+ r#"

173+ name = "remove_users_email_column"

174+

175+ [[actions]]

176+ type = "remove_column"

177+ table = "users"

178+ column = "email"

179+

180+ [actions.down]

181+ table = "profiles"

182+ value = "profiles.email"

183+ where = "users.id = profiles.user_id"

184+ "#,

185+ );

186+

187+ test.after_first(|db| {

188+ db.simple_query("INSERT INTO users (id, email) VALUES (1, 'test@example.com')")

189+ .unwrap();

190+ db.simple_query("INSERT INTO profiles (user_id, email) VALUES (1, 'test@example.com')")

191+ .unwrap();

192+ });

193+

194+ test.intermediate(|old_db, new_db| {

195+ new_db

196+ .simple_query("UPDATE profiles SET email = 'test2@example.com' WHERE user_id = 1")

197+ .unwrap();

198+

199+ // Ensure new email was propagated to users table in old schema

200+ let email: String = old_db

201+ .query(

202+ "

203+ SELECT email

204+ FROM users

205+ WHERE id = 1

206+ ",

207+ &[],

208+ )

209+ .unwrap()

210+ .first()

211+ .map(|row| row.get("email"))

212+ .unwrap();

213+ assert_eq!("test2@example.com", email);

214+ });

215+

216+ test.run();

131}

217}

tests/remove_table.rs+2

@@ -39,4 +39,6 @@ fn remove_table() {

39 // Ensure the table is not accessible through the new schema

40 assert!(new_db.query("SELECT id FROM users", &[]).is_err());

41 });

42+

43+ test.run();

42}

44}