6034dfe...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+3−3

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

1[package]

2name = "reshape"

3−version = "0.6.1"

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"] }

@@ -23,4 +23,4 @@ version = "3.0.0"

23colored = "2"

24rand = "0.8"

25dotenv = "0.15.0"

26−lexical-sort = "0.3.1"

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+89−14

@@ -2,7 +2,7 @@

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

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)!

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/).

@@ -167,7 +167,7 @@ Every action has a `type`. The supported types are detailed below.

167

168#### Create table

169

170−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.

171

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

173

@@ -226,6 +226,29 @@ primary_key = ["id"]

226 referenced_columns = ["id"]

227```

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+

229#### Rename table

252#### Rename table

230

253

231The `rename_table` action will change the name of an existing table.

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

@@ -477,8 +500,8 @@ column = "email"

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

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

478 [actions.down]

501 [actions.down]

479 table = "profiles"

502 table = "profiles"

480− value = "email"

503+ value = "profiles.email"

481− where = "id = user_id"

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

482```

505```

483

506

484### Indices

507### Indices

@@ -599,11 +622,26 @@ abort = """

599

622

600### Complex changes across tables

623### Complex changes across tables

601

624

602−The `up` and `down` options available for many actions can also perform more complex changes that span tables.

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

603

626

604_Example: move `email` column from `users` to `profiles` table_

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

605

628

606```toml

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+

607[[actions]]

645[[actions]]

608type = "remove_column"

646type = "remove_column"

609table = "users"

647table = "users"

@@ -612,23 +650,60 @@ column = "email"

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

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

613 [actions.down]

651 [actions.down]

614 table = "profiles"

652 table = "profiles"

615− value = "email"

653+ value = "profiles.email"

616− where = "id = user_id"

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`_

617

658

659+```toml

660+# Add `user_account_connections` as a junction table

618[[actions]]

661[[actions]]

619−type = "add_column"

662+type = "create_table"

620−table = "profiles"

663+name = "user_account_connections"

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

621

665

666+ [[actions.columns]]

667+ name = "account_id"

668+ type = "INTEGER"

669+

622− [actions.column]

670+ [[actions.columns]]

623− name = "email"

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"

624 type = "TEXT"

677 type = "TEXT"

625 nullable = false

678 nullable = false

626

679

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

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

628 [actions.up]

681 [actions.up]

629 table = "users"

682 table = "users"

630− value = "email"

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"

631− where = "user_id = 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"

632```

707```

633

708

634## Commands and options

709## Commands and options

src/migrations/add_column.rs+117−25

@@ -3,7 +3,7 @@ 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)]

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

43 )

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+

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

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

47 format!(

56 format!(

48 "{}_add_column_not_null_{}_{}",

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

@@ -72,7 +81,7 @@ impl Action for AddColumn {

72 let temp_column_name = self.temp_column_name(ctx);

81 let temp_column_name = self.temp_column_name(ctx);

74 let mut definition_parts = vec![

83 let mut definition_parts = vec![

75− temp_column_name.to_string(),

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

76 self.column.data_type.to_string(),

85 self.column.data_type.to_string(),

77 ];

86 ];

@@ -97,21 +106,21 @@ impl Action for AddColumn {

97 );

106 );

98 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+

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

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

101 if let Transformation::Simple(up) = up {

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

102− let declarations: Vec<String> = table

103− .columns

104− .iter()

105− .map(|column| {

106− format!(

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

108− table = table.real_name,

109− alias = column.name,

110− real_name = column.real_name,

111− )

112− })

113− .collect();

114−

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

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

116 let query = format!(

125 let query = format!(

117 r#"

126 r#"

@@ -122,7 +131,7 @@ impl Action for AddColumn {

122 DECLARE

131 DECLARE

123 {declarations}

132 {declarations}

124 BEGIN

133 BEGIN

125− NEW.{temp_column_name} = {up};

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

126 END;

135 END;

127 END IF;

136 END IF;

128 RETURN NEW;

137 RETURN NEW;

@@ -151,15 +160,20 @@ impl Action for AddColumn {

151 r#where,

160 r#where,

152 } = up

161 } = up

153 {

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+

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

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

155

169

156− let declarations: Vec<String> = from_table

170+ let from_table_assignments: Vec<String> = from_table

157 .columns

171 .columns

158 .iter()

172 .iter()

159 .map(|column| {

173 .map(|column| {

160 format!(

174 format!(

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

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

162− table = from_table.real_name,

176+ table = from_table.name,

163 alias = column.name,

177 alias = column.name,

164 real_name = column.real_name,

178 real_name = column.real_name,

165 )

179 )

@@ -175,11 +189,18 @@ impl Action for AddColumn {

175 BEGIN

189 BEGIN

176 IF NOT reshape.is_new_schema() THEN

190 IF NOT reshape.is_new_schema() THEN

177 DECLARE

191 DECLARE

178− {declarations}

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

179 BEGIN

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+

180 UPDATE public."{changed_table_real}"

199 UPDATE public."{changed_table_real}"

181 SET "{temp_column_name}" = {value}

200 SET "{temp_column_name}" = {value}

182 WHERE {where};

201 WHERE {where};

202+

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

183 END;

204 END;

184 END IF;

205 END IF;

185 RETURN NEW;

206 RETURN NEW;

@@ -189,14 +210,81 @@ impl Action for AddColumn {

189 DROP TRIGGER IF EXISTS "{trigger_name}" ON "{from_table_real}";

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

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

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

191 "#,

212 "#,

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

192 changed_table_real = table.real_name,

214 changed_table_real = table.real_name,

215+ from_table = from_table.name,

193 from_table_real = from_table.real_name,

216 from_table_real = from_table.real_name,

194 trigger_name = self.trigger_name(ctx),

217 trigger_name = self.trigger_name(ctx),

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

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

196 temp_column_name = temp_column_name,

219 temp_column_name = temp_column_name,

197 );

220 );

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

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

199

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+

200 // Backfill values in batches by touching the from table

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

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

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

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

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

@@ -210,10 +298,10 @@ impl Action for AddColumn {

210 if !self.column.nullable {

298 if !self.column.nullable {

211 let query = format!(

299 let query = format!(

212 r#"

300 r#"

213− ALTER TABLE "{table}"

301+ ALTER TABLE "{table}"

214− ADD CONSTRAINT "{constraint_name}"

302+ ADD CONSTRAINT "{constraint_name}"

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

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

216− "#,

304+ "#,

217 table = self.table,

305 table = self.table,

218 constraint_name = self.not_null_constraint_name(ctx),

306 constraint_name = self.not_null_constraint_name(ctx),

219 column = temp_column_name,

307 column = temp_column_name,

@@ -236,8 +324,10 @@ impl Action for AddColumn {

236 let query = format!(

324 let query = format!(

237 r#"

325 r#"

238 DROP FUNCTION IF EXISTS "{trigger_name}" CASCADE;

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

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

239 "#,

328 "#,

240 trigger_name = self.trigger_name(ctx),

329 trigger_name = self.trigger_name(ctx),

330+ reverse_trigger_name = self.reverse_trigger_name(ctx),

241 );

331 );

242 transaction

332 transaction

243 .run(&query)

333 .run(&query)

@@ -329,8 +419,10 @@ impl Action for AddColumn {

329 let query = format!(

419 let query = format!(

330 r#"

420 r#"

331 DROP FUNCTION IF EXISTS "{trigger_name}" CASCADE;

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

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

332 "#,

423 "#,

333 trigger_name = self.trigger_name(ctx),

424 trigger_name = self.trigger_name(ctx),

425+ reverse_trigger_name = self.reverse_trigger_name(ctx),

334 );

426 );

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

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

336

428

src/migrations/remove_column.rs+247−30

@@ -3,7 +3,7 @@ use crate::{

3 db::{Conn, Transaction},

4 schema::Schema,

5};

6−use anyhow::{bail, Context};

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

7use serde::{Deserialize, Serialize};

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

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

33 self.column

34 )

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+ }

36}

63}

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

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

@@ -51,6 +78,9 @@ impl Action for RemoveColumn {

51 schema: &Schema,

78 schema: &Schema,

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

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

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

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))?;

55 // Add down trigger

85 // Add down trigger

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

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

@@ -109,22 +139,76 @@ impl Action for RemoveColumn {

109

139

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

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

111

141

112− let declarations: Vec<String> = from_table

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 $$

151+ BEGIN

152+ IF NOT reshape.is_new_schema() THEN

153+ IF NEW.{column} IS NULL THEN

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

155+ END IF;

156+ END IF;

157+ RETURN NEW;

158+ END

159+ $$ language 'plpgsql';

160+

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

167+ EXECUTE PROCEDURE {trigger_name}();

168+ "#,

169+ table = self.table,

170+ trigger_name = self.not_null_constraint_trigger_name(ctx),

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+ "#,

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

113 .columns

200 .columns

114 .iter()

201 .iter()

115 .map(|column| {

202 .map(|column| {

116 format!(

203 format!(

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

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

118− table = from_table.real_name,

119 alias = column.name,

205 alias = column.name,

120 real_name = column.real_name,

206 real_name = column.real_name,

121 )

207 )

122 })

208 })

123− .collect();

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

210+ .join(", ");

124

211

125− // TODO: If column is NOT NULL, remove the constraint and perform a NULL check in some other way.

126− // Otherwise, it's not possible to update the NOT NULL column from another table even in the same transaction.

127− // Either make the NULL check in here or maybe use a constraint trigger: https://www.postgresql.org/docs/9.0/sql-createconstraint.html.

128 let query = format!(

212 let query = format!(

129 r#"

213 r#"

130 CREATE OR REPLACE FUNCTION {trigger_name}()

214 CREATE OR REPLACE FUNCTION {trigger_name}()

@@ -133,11 +217,21 @@ impl Action for RemoveColumn {

133 BEGIN

217 BEGIN

134 IF reshape.is_new_schema() THEN

218 IF reshape.is_new_schema() THEN

135 DECLARE

219 DECLARE

136− {declarations}

220+ {from_table} record;

137 BEGIN

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+

138 UPDATE "migration_{existing_schema_name}"."{changed_table}" "{changed_table}"

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

139 SET "{column_name}" = {value}

231 SET "{column_name}" = {value}

140 WHERE {where};

232 WHERE {where};

233+

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

141 END;

235 END;

142 END IF;

236 END IF;

143 RETURN NEW;

237 RETURN NEW;

@@ -148,12 +242,80 @@ impl Action for RemoveColumn {

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

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

149 "#,

243 "#,

150 changed_table = self.table,

244 changed_table = self.table,

245+ from_table = from_table.name,

151 from_table_real = from_table.real_name,

246 from_table_real = from_table.real_name,

152 column_name = self.column,

247 column_name = self.column,

153 trigger_name = self.trigger_name(ctx),

248 trigger_name = self.trigger_name(ctx),

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

155 );

249 );

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

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),

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

316+ );

317+ db.run(&query)

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

157 }

319 }

158 }

320 }

159

321

@@ -179,25 +341,20 @@ impl Action for RemoveColumn {

179 }

341 }

180

342

181 // Remove column, function and trigger

343 // Remove column, function and trigger

182− let trigger_table = match &self.down {

183− Some(Transformation::Update {

184− table,

185− value: _,

186− r#where: _,

187− }) => table,

188− _ => &self.table,

189− };

190 let query = format!(

344 let query = format!(

191 r#"

345 r#"

192 ALTER TABLE "{table}"

346 ALTER TABLE "{table}"

193 DROP COLUMN IF EXISTS "{column}";

347 DROP COLUMN IF EXISTS "{column}";

194

348

195− DROP TRIGGER IF EXISTS "{trigger_name}" ON "{trigger_table}";

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

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

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

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

197 "#,

352 "#,

198 table = self.table,

353 table = self.table,

199 column = self.column,

354 column = self.column,

200 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),

201 );

358 );

202 db.run(&query)

359 db.run(&query)

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

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

@@ -214,21 +371,81 @@ impl Action for RemoveColumn {

214 }

371 }

215

372

216 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+

217 // Remove function and trigger

439 // Remove function and trigger

218− let trigger_table = match &self.down {

219− Some(Transformation::Update {

220− table,

221− value: _,

222− r#where: _,

223− }) => table,

224− _ => &self.table,

225− };

226 db.run(&format!(

440 db.run(&format!(

227 r#"

441 r#"

228− DROP TRIGGER IF EXISTS "{trigger_name}" ON "{trigger_table}";

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

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

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

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

230 "#,

445 "#,

231 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),

232 ))

449 ))

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

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

234

451

tests/add_column.rs+2−2

@@ -308,8 +308,8 @@ fn add_column_with_complex_up() {

308

309 [actions.up]

310 table = "users"

311− value = "email"

311+ value = "users.email"

312− where = "user_id = id"

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

313 "#,

314 );

315

tests/complex.rs+174−5

@@ -1,6 +1,165 @@

1mod common;

2use 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+

4#[test]

163#[test]

5fn extract_relation_into_new_table() {

164fn extract_relation_into_new_table() {

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

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

@@ -30,10 +189,12 @@ fn extract_relation_into_new_table() {

30 [[actions.columns]]

189 [[actions.columns]]

31 name = "account_id"

190 name = "account_id"

32 type = "INTEGER"

191 type = "INTEGER"

192+ nullable = false

193

34 [[actions.columns]]

194 [[actions.columns]]

35 name = "account_role"

195 name = "account_role"

36 type = "TEXT"

196 type = "TEXT"

197+ nullable = false

37 "#,

198 "#,

38 );

199 );

200

@@ -57,11 +218,12 @@ fn extract_relation_into_new_table() {

57 [[actions.columns]]

218 [[actions.columns]]

58 name = "role"

219 name = "role"

59 type = "TEXT"

220 type = "TEXT"

221+ nullable = false

222

61 [actions.up]

223 [actions.up]

62 table = "users"

224 table = "users"

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

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

64− where = "user_id = id"

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

227

66 [[actions]]

228 [[actions]]

67 type = "remove_column"

229 type = "remove_column"

@@ -70,8 +232,8 @@ fn extract_relation_into_new_table() {

232

71 [actions.down]

233 [actions.down]

72 table = "user_account_connections"

234 table = "user_account_connections"

73− value = "account_id"

235+ value = "user_account_connections.account_id"

74− where = "id = user_id"

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

237

76 [[actions]]

238 [[actions]]

77 type = "remove_column"

239 type = "remove_column"

@@ -80,8 +242,8 @@ fn extract_relation_into_new_table() {

242

81 [actions.down]

243 [actions.down]

82 table = "user_account_connections"

244 table = "user_account_connections"

83− value = "LOWER(role)"

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

84− where = "id = user_id"

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

85 "#,

247 "#,

86 );

248 );

249

@@ -134,6 +296,13 @@ fn extract_relation_into_new_table() {

134 == 1

296 == 1

135 );

297 );

136

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+

137 // Ensure updated user role in old schema updates connection in new schema

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

138 old_db

307 old_db

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

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

tests/remove_column.rs+2−2

@@ -179,8 +179,8 @@ fn remove_column_with_complex_down() {

179

180 [actions.down]

181 table = "profiles"

182− value = "email"

182+ value = "profiles.email"

183− where = "id = user_id"

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

184 "#,

185 );

186