9752b1e · reshape · git.iko.soy

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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)

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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)!

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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/).

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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

246 [actions.up]

247 [actions.up]

247 table = "users"

248 table = "users"

248 values = { user_id = "id", user_email = "email" }

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

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622

622### Complex changes across tables

623### Complex changes across tables

623

624

624−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.

625

626

626_Example: move `email` column from `users` to `profiles` table_

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

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628

653 where = "user_id = id"

654 where = "user_id = id"

654```

655```

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+

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

680+ [actions.up]

681+ table = "users"

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

683+ where = "user_id = id"

684+

685+[[actions]]

686+type = "remove_column"

687+table = "users"

688+column = "account_id"

689+

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

691+ [actions.down]

692+ table = "user_account_connections"

693+ value = "account_id"

694+ where = "id = user_id"

695+

696+[[actions]]

697+type = "remove_column"

698+table = "users"

699+column = "account_role"

700+

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

702+ [actions.down]

703+ table = "user_account_connections"

704+ value = "LOWER(role)"

705+ where = "id = user_id"

706+```

707+

656## Commands and options

708## Commands and options

657

709

658### `reshape migration start`

710### `reshape migration start`