Database Migrations

Database migrations are SQL statements that create, update, or delete your existing database schemas. They are a common way of tracking changes to your database over time.

Schema migrations

For this guide, we'll create a table called employees and see how we can make changes to it.

You will need to install the Supabase CLI and start the local development stack.

If a lock timeout error occurs, in your migration file, consider increasing your lock_timeout setting.

<StepHikeCompact.Step step={1}> <StepHikeCompact.Details title="Create your first migration file"> To get started, generate a new migration to store the SQL needed to create our employees table. </StepHikeCompact.Details>

<StepHikeCompact.Code>

supabase migration new create_employees_table

</StepHikeCompact.Code>

</StepHikeCompact.Step> </StepHikeCompact>

<StepHikeCompact.Step step={2}> <StepHikeCompact.Details title="Add the SQL to your migration file"> This creates a new migration file in supabase/migrations directory.

  To that file, add the SQL to create this `employees` table.
</StepHikeCompact.Details>

<StepHikeCompact.Code>

create table if not exists employees (
  id bigint primary key generated always as identity,
  name text not null,
  email text,
  created_at timestamptz default now()
);

</StepHikeCompact.Code>

</StepHikeCompact.Step> </StepHikeCompact>

<StepHikeCompact.Step step={3}> <StepHikeCompact.Details title="Apply your first migration"> Run this migration to create the employees table.

  Now you can visit your new `employees` table in the local Dashboard.
</StepHikeCompact.Details>

<StepHikeCompact.Code>

supabase migration up

</StepHikeCompact.Code>

</StepHikeCompact.Step> </StepHikeCompact>

<StepHikeCompact.Step step={4}> <StepHikeCompact.Details title="Modify your employees table"> Next, modify your employees table by adding a column for department. </StepHikeCompact.Details>

<StepHikeCompact.Code>

supabase migration new add_department_column

</StepHikeCompact.Code>

</StepHikeCompact.Step> </StepHikeCompact>

<StepHikeCompact.Step step={5}> <StepHikeCompact.Details title="Add a new column to your table"> To that new migration file, add the SQL to create a new department column. </StepHikeCompact.Details>

<StepHikeCompact.Code>

alter table if exists public.employees
add department text default 'Hooli';

</StepHikeCompact.Code>

</StepHikeCompact.Step> </StepHikeCompact>

<StepHikeCompact.Step step={6}> <StepHikeCompact.Details title="Apply your second migration"> Run this migration to update your existing employees table. </StepHikeCompact.Details>

<StepHikeCompact.Code>

supabase migration up

</StepHikeCompact.Code>

</StepHikeCompact.Step> </StepHikeCompact>

Finally, you should see the department column added to your employees table in the local Dashboard.

View the complete code for this example on GitHub.

Seeding data

Now that you are managing your database with migrations, it would be great have some seed data to use every time you reset the database.

<StepHikeCompact.Step step={1}> <StepHikeCompact.Details title="Populate your table"> Create a seed script in supabase/seed.sql.

  To that file, add the SQL to insert data into your `employees` table.
</StepHikeCompact.Details>

<StepHikeCompact.Code>

insert into public.employees
  (name)
values
  ('Erlich Bachman'),
  ('Richard Hendricks'),
  ('Monica Hall');

</StepHikeCompact.Code>

</StepHikeCompact.Step> </StepHikeCompact>

<StepHikeCompact.Step step={2}> <StepHikeCompact.Details title="Reset your database"> Reset your database to reapply migrations and populate with seed data. </StepHikeCompact.Details>

<StepHikeCompact.Code>

supabase db reset

</StepHikeCompact.Code>

</StepHikeCompact.Step> </StepHikeCompact>

You should now see the employees table, along with your seed data in the Dashboard! All of your database changes are captured in code, and you can reset to a known state at any time, complete with seed data.

Diffing changes

This workflow is great if you know SQL and are comfortable creating tables and columns. If not, you can still use the Dashboard to create tables and columns, and then use the CLI to diff your changes and create migrations.

Only use the Dashboard to make schema changes on your local database, then capture them with supabase db diff. Making schema changes directly on your remote database (via the SQL editor or Table Editor) bypasses the migration history and will cause db push to fail with sync errors. Once you're using migrations, all schema changes to your remote database should go through migration files only.

<StepHikeCompact.Step step={1}> <StepHikeCompact.Details title="Create your table from the Dashboard"> Create a new table called cities, with columns id, name and population.

  Then generate a [schema diff](/docs/reference/cli/supabase-db-diff).
</StepHikeCompact.Details>

<StepHikeCompact.Code>

supabase db diff -f create_cities_table

</StepHikeCompact.Code>

</StepHikeCompact.Step> </StepHikeCompact>

<StepHikeCompact.Step step={2}> <StepHikeCompact.Details title="Add schema diff as a migration"> A new migration file is created for you.

  Alternately, you can copy the table definitions directly from the Table Editor.
</StepHikeCompact.Details>

<StepHikeCompact.Code>

create table "public"."cities" (
  "id" bigint primary key generated always as identity,
  "name" text,
  "population" bigint
);

</StepHikeCompact.Code>

</StepHikeCompact.Step> </StepHikeCompact>

<StepHikeCompact.Step step={3}> <StepHikeCompact.Details title="Test your migration"> Test your new migration file by resetting your local database. </StepHikeCompact.Details>

<StepHikeCompact.Code>

supabase db reset

</StepHikeCompact.Code>

</StepHikeCompact.Step> </StepHikeCompact>

The last step is deploying these changes to a live Supabase project.

Deploy your project

You've been developing your project locally, making changes to your tables via migrations. It's time to deploy your project to the Supabase Platform and start scaling up to millions of users!

Head over to Supabase and create a new project to deploy to.

<StepHikeCompact.Step step={1}> <StepHikeCompact.Details title="Log in to the Supabase CLI"> Login to the Supabase CLI using an auto-generated Personal Access Token. </StepHikeCompact.Details>

<StepHikeCompact.Code>

supabase login

</StepHikeCompact.Code>

</StepHikeCompact.Step> </StepHikeCompact>

<StepHikeCompact.Step step={2}> <StepHikeCompact.Details title="Link your project"> Link to your remote project by selecting from the on-screen prompt. </StepHikeCompact.Details>

<StepHikeCompact.Code>

supabase link

</StepHikeCompact.Code>

</StepHikeCompact.Step> </StepHikeCompact>

<StepHikeCompact.Step step={3}> <StepHikeCompact.Details title="Deploy database migrations"> Push your migrations to the remote database. </StepHikeCompact.Details>

<StepHikeCompact.Code>

supabase db push

</StepHikeCompact.Code>

</StepHikeCompact.Step> </StepHikeCompact>

<StepHikeCompact.Step step={4}> <StepHikeCompact.Details title="Deploy database seed data (optional)"> Push your migrations and seed the remote database. </StepHikeCompact.Details>

<StepHikeCompact.Code>

supabase db push --include-seed

</StepHikeCompact.Code>

</StepHikeCompact.Step> </StepHikeCompact>

Visiting your live project on Supabase, you'll see a new employees table, complete with the department column you added in the second migration above.

Working with a team

When multiple developers share a Supabase project, a few rules keep migrations from getting out of sync.

The golden rule: never change the remote database directly. Once you're using migrations, all schema changes — even small ones — should go through migration files. Using the Dashboard's SQL editor or Table Editor on your remote database bypasses the migration history, and db push will start failing with sync errors.

The team workflow:

<StepHikeCompact.Step step={1}> <StepHikeCompact.Details title="Create a migration locally"> Each developer creates migration files on their own branch, never touching the remote database directly. </StepHikeCompact.Details>

<StepHikeCompact.Code>

supabase migration new your_change_description

</StepHikeCompact.Code>

</StepHikeCompact.Step>

<StepHikeCompact.Step step={2}> <StepHikeCompact.Details title="Test and commit"> Reset your local database to apply the migration, then commit the migration file to git. </StepHikeCompact.Details>

<StepHikeCompact.Code>

supabase db reset
git add supabase/migrations
git commit -m "add migration: your_change_description"

</StepHikeCompact.Code>

</StepHikeCompact.Step>

<StepHikeCompact.Step step={3}> <StepHikeCompact.Details title="Pull and reset when a teammate merges a migration"> After pulling new migration files from git, reset your local database to apply them. </StepHikeCompact.Details>

<StepHikeCompact.Code>

git pull
supabase db reset

</StepHikeCompact.Code>

</StepHikeCompact.Step>

<StepHikeCompact.Step step={4}> <StepHikeCompact.Details title="One person deploys to remote"> Coordinate so only one person runs db push at a time. Migration files are applied in timestamp order, so concurrent pushes from different machines can cause conflicts. </StepHikeCompact.Details>

<StepHikeCompact.Code>

supabase db push

</StepHikeCompact.Code>

</StepHikeCompact.Step>

For a more automated deployment approach, consider using Supabase Branching or a CI/CD pipeline that runs supabase db push on merge to your main branch.

Diagnosing and fixing sync errors

If db push fails with errors suggesting you run supabase migration repair, your local migration files and the remote database's migration history are out of sync. Here's how to diagnose and fix it.

How migration tracking works

Supabase tracks which migrations have been applied on each database in a table called supabase_migrations.schema_migrations. When you run supabase db push, it compares your local supabase/migrations folder against that table and runs only the ones not yet applied, in order.

Git tracks your migration files. Supabase tracks what's been applied to each database. These are two separate systems that need to stay in sync.

Step 1: Check what's out of sync

Start by listing the migration status across local and remote:

supabase migration list

This shows which migrations are applied locally, which are applied on the remote, and where they diverge.

Step 2: If you made changes on the remote database directly

Pull the current remote state into a migration file to get back in sync:

supabase db pull

This creates a new migration file capturing the current remote schema. Commit it to git, then follow the standard workflow going forward.

Step 3: If the migration history table is wrong

If a migration shows as missing in the remote history table but the schema change is actually already there (for example, it was applied manually), you can mark it as applied without re-running it:

supabase migration repair --status applied <migration-timestamp>

Or if a migration is recorded as applied but was never actually run:

supabase migration repair --status reverted <migration-timestamp>

migration repair updates the tracking table only — it does not apply or revert any SQL. Use it to correct the history record when you know the actual database state is correct.