migrate() — drizzle-orm Function Reference

Architecture documentation for the migrate() function in migrator.ts from the drizzle-orm codebase.

Function typescript DrizzleORM SQLDialects

Entity Profile

DrizzleORM→ SQLDialects→ migrate() — drizzle-orm Function Reference

Dependency Diagram

graph TD
  dc8ddbe9_3119_1dd2_ca6b_c3d8c97aa4b9["migrate()"]
  b4ea4a73_2f21_2ebc_d7d0_3e4301b07007["migrator.ts"]
  dc8ddbe9_3119_1dd2_ca6b_c3d8c97aa4b9 -->|defined in| b4ea4a73_2f21_2ebc_d7d0_3e4301b07007
  style dc8ddbe9_3119_1dd2_ca6b_c3d8c97aa4b9 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

drizzle-orm/src/sqlite-proxy/migrator.ts lines 8–49

export async function migrate<TSchema extends Record<string, unknown>>(
	db: SqliteRemoteDatabase<TSchema>,
	callback: ProxyMigrator,
	config: MigrationConfig,
) {
	const migrations = readMigrationFiles(config);

	const migrationsTable = typeof config === 'string'
		? '__drizzle_migrations'
		: config.migrationsTable ?? '__drizzle_migrations';

	const migrationTableCreate = sql`
		CREATE TABLE IF NOT EXISTS ${sql.identifier(migrationsTable)} (
			id SERIAL PRIMARY KEY,
			hash text NOT NULL,
			created_at numeric
		)
	`;

	await db.run(migrationTableCreate);

	const dbMigrations = await db.values<[number, string, string]>(
		sql`SELECT id, hash, created_at FROM ${sql.identifier(migrationsTable)} ORDER BY created_at DESC LIMIT 1`,
	);

	const lastDbMigration = dbMigrations[0] ?? undefined;

	const queriesToRun: string[] = [];
	for (const migration of migrations) {
		if (
			!lastDbMigration
			|| Number(lastDbMigration[2])! < migration.folderMillis
		) {
			queriesToRun.push(
				...migration.sql,
				`INSERT INTO \`${migrationsTable}\` ("hash", "created_at") VALUES('${migration.hash}', '${migration.folderMillis}')`,
			);
		}
	}

	await callback(queriesToRun);
}