PgDialect Class — drizzle-orm Architecture

Source Code

drizzle-orm/src/pg-core/dialect.ts lines 63–1445

export class PgDialect {
	static readonly [entityKind]: string = 'PgDialect';

	/** @internal */
	readonly casing: CasingCache;

	constructor(config?: PgDialectConfig) {
		this.casing = new CasingCache(config?.casing);
	}

	async migrate(migrations: MigrationMeta[], session: PgSession, config: string | MigrationConfig): Promise<void> {
		const migrationsTable = typeof config === 'string'
			? '__drizzle_migrations'
			: config.migrationsTable ?? '__drizzle_migrations';
		const migrationsSchema = typeof config === 'string' ? 'drizzle' : config.migrationsSchema ?? 'drizzle';
		const migrationTableCreate = sql`
			CREATE TABLE IF NOT EXISTS ${sql.identifier(migrationsSchema)}.${sql.identifier(migrationsTable)} (
				id SERIAL PRIMARY KEY,
				hash text NOT NULL,
				created_at bigint
			)
		`;
		await session.execute(sql`CREATE SCHEMA IF NOT EXISTS ${sql.identifier(migrationsSchema)}`);
		await session.execute(migrationTableCreate);

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

		const lastDbMigration = dbMigrations[0];
		await session.transaction(async (tx) => {
			for await (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 ${sql.identifier(migrationsSchema)}.${
							sql.identifier(migrationsTable)
						} ("hash", "created_at") values(${migration.hash}, ${migration.folderMillis})`,
					);
				}
			}
		});
	}

	escapeName(name: string): string {
		return `"${name}"`;
	}

	escapeParam(num: number): string {
		return `$${num + 1}`;
	}

	escapeString(str: string): string {
		return `'${str.replace(/'/g, "''")}'`;
	}

	private buildWithCTE(queries: Subquery[] | undefined): SQL | undefined {
		if (!queries?.length) return undefined;

		const withSqlChunks = [sql`with `];
		for (const [i, w] of queries.entries()) {
			withSqlChunks.push(sql`${sql.identifier(w._.alias)} as (${w._.sql})`);
			if (i < queries.length - 1) {
				withSqlChunks.push(sql`, `);
			}
		}
		withSqlChunks.push(sql` `);
		return sql.join(withSqlChunks);
	}

	buildDeleteQuery({ table, where, returning, withList }: PgDeleteConfig): SQL {
		const withSql = this.buildWithCTE(withList);

		const returningSql = returning