Data migrations are handled via the Knex migration system.
Migrations provide a managed and version-control-backed method for modifying the data structures that support the API.
Adding A Migration
yarn add-migration <newMigrationName>
creates a duplicate of migration.stub.ts that
includes
-the needed module-alias import and
-a standard/initial TS up/down export setup.
Running A Migration
You’ll first need to build the app to compile the TypeScript migration into JavaScript, then run the migration.
yarn
yarn build
yarn db-latest
Data Structure Notes
Defining Primary Keys
In the Knex migration use the increments data type for a primary key field. For PostgreSQL this will be a serial data type, a 4-byte integer.
await knex.schema.createTable(tableName, (table) => {
table.increments('id');Foreign Key => Primary Key References
For foreign key references, use the integer type which is also 4-bytes.
Adding a new column and making it a FK for it.
table.integer('cert_marks_id');
table.foreign('cert_marks').references('cert_marks.id');