migrate() — drizzle-orm Function Reference

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

Function typescript DrizzleORM SQLDialects calls 1

Entity Profile

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

Dependency Diagram

graph TD
  fa772623_beb4_6a0e_616a_092d0565b6b1["migrate()"]
  9c5eee4c_4b78_a585_4038_d710de212097["MySqlDialect"]
  fa772623_beb4_6a0e_616a_092d0565b6b1 -->|defined in| 9c5eee4c_4b78_a585_4038_d710de212097
  a2614cb2_5d7d_d96b_b795_d1927ebdc101["values()"]
  fa772623_beb4_6a0e_616a_092d0565b6b1 -->|calls| a2614cb2_5d7d_d96b_b795_d1927ebdc101
  style fa772623_beb4_6a0e_616a_092d0565b6b1 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

drizzle-orm/src/mysql-core/dialect.ts lines 54–92

	async migrate(
		migrations: MigrationMeta[],
		session: MySqlSession,
		config: Omit<MigrationConfig, 'migrationsSchema'>,
	): Promise<void> {
		const migrationsTable = 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 bigint
			)
		`;
		await session.execute(migrationTableCreate);

		const dbMigrations = await session.all<{ id: number; hash: string; created_at: string }>(
			sql`select id, hash, created_at from ${sql.identifier(migrationsTable)} order by created_at desc limit 1`,
		);

		const lastDbMigration = dbMigrations[0];

		await session.transaction(async (tx) => {
			for (const migration of migrations) {
				if (
					!lastDbMigration
					|| Number(lastDbMigration.created_at) < migration.folderMillis
				) {
					for (const stmt of migration.sql) {
						await tx.execute(sql.raw(stmt));
					}
					await tx.execute(
						sql`insert into ${
							sql.identifier(migrationsTable)
						} (\`hash\`, \`created_at\`) values(${migration.hash}, ${migration.folderMillis})`,
					);
				}
			}
		});
	}