Function construct

drizzle-orm/src/mysql2/driver.ts:60–111

(
	client: TClient,
	config: MySql2DrizzleConfig<TSchema> = {},
)

	& ({ schema: TSchema; mode: Mode } | { schema?: undefined; mode?: Mode });

function construct<
	TSchema extends Record<string, unknown> = Record<string, never>,
	TClient extends Pool | Connection | CallbackPool | CallbackConnection = CallbackPool,
>(
	client: TClient,
	config: MySql2DrizzleConfig<TSchema> = {},
): MySql2Database<TSchema> & {
	$client: AnyMySql2Connection extends TClient ? CallbackPool : TClient;
} {
	const dialect = new MySqlDialect({ casing: config.casing });
	let logger;
	if (config.logger === true) {
		logger = new DefaultLogger();
	} else if (config.logger !== false) {
		logger = config.logger;
	}

	const clientForInstance = isCallbackClient(client) ? client.promise() : client;

	let schema: RelationalSchemaConfig<TablesRelationalConfig> | undefined;
	if (config.schema) {
		if (config.mode === undefined) {
			throw new DrizzleError({
				message:
					'You need to specify "mode": "planetscale" or "default" when providing a schema. Read more: https://orm.drizzle.team/docs/rqb#modes',
			});
		}

		const tablesConfig = extractTablesRelationalConfig(
			config.schema,
			createTableRelationsHelpers,
		);
		schema = {
			fullSchema: config.schema,
			schema: tablesConfig.tables,
			tableNamesMap: tablesConfig.tableNamesMap,
		};
	}

	const mode = config.mode ?? 'default';

	const driver = new MySql2Driver(clientForInstance as MySql2Client, dialect, { logger, cache: config.cache });
	const session = driver.createSession(schema, mode);
	const db = new MySql2Database(dialect, session, schema as any, mode) as MySql2Database<TSchema>;
	(<any> db).$client = client;
	(<any> db).$cache = config.cache;
	if ((<any> db).$cache) {
		(<any> db).$cache['invalidate'] = config.cache?.onMutate;
	}

	return db as any;
}

interface CallbackClient {
	promise(): MySql2Client;