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Schema Management

Tether automates the management of your local SQLite database schema by mirroring the Postgres schema from your Supabase project. This includes handling migrations, creating tables, and managing relationships.

As SQLite is a full SQL database, you have to manage migrations of the local schema over time when you change the schema in your Supabase project so that you can persist the existing data in running installations of your application.

Tether will configure and manage these for you.

Schema Generation​

When you run the generator, Tether will:

  • Fetch the schema from your Supabase project.
  • Create files in /lib/database/schema that represent the schema. The system will compare these over time to create migrations.
  • Generate the necessary SQLite commands to create the tables and relationships in your local SQLite database.
  • Create a supabase_schema.dart file that is a snapshot of the current schema. This file is used by the managers to interact with relationships.
  • Create migrations for the local SQLite database in lib/database/sqlite_migrations.
  • Create the database files for the local SQLite database. Typically at lib/database/database.dart.

Schema Conventions​

Tether will try to following:

  • Use the same table names as in your Supabase project. i.e. user_profiles in Supabase will be user_profiles in SQLite.
  • Use the same column names as in your Supabase project. i.e. some_column in Supabase will be some_column in SQLite.
  • Use the same data types as in your Supabase project or will transform them to the closest equivalent in SQLite. Most data types will be mapped to the corred Dart type by the Models system.
  • Use the same relationships as in your Supabase project. i.e. a profiles table with a foreign key to a users table will create a relationship in the SQLite database.
  • Use the same indexes as in your Supabase project. i.e. a profiles table with an index on the email column will create an index in the SQLite database.

Tether does not currently provide a way to manually define things like indexes on the local DB outside of the automatic generation.

Best Practices​

  • Tether will automatically rename column that are reserved words in Dart. For example, a column named default in Supabase will be renamed to defaultValue in SQLite.