MySqlDatabase Class — drizzle-orm Architecture

Source Code

drizzle-orm/src/mysql-core/db.ts lines 34–489

export class MySqlDatabase<
	TQueryResult extends MySqlQueryResultHKT,
	TPreparedQueryHKT extends PreparedQueryHKTBase,
	TFullSchema extends Record<string, unknown> = {},
	TSchema extends TablesRelationalConfig = ExtractTablesWithRelations<TFullSchema>,
> {
	static readonly [entityKind]: string = 'MySqlDatabase';

	declare readonly _: {
		readonly schema: TSchema | undefined;
		readonly fullSchema: TFullSchema;
		readonly tableNamesMap: Record<string, string>;
	};

	query: TFullSchema extends Record<string, never>
		? DrizzleTypeError<'Seems like the schema generic is missing - did you forget to add it to your DB type?'>
		: {
			[K in keyof TSchema]: RelationalQueryBuilder<TPreparedQueryHKT, TSchema, TSchema[K]>;
		};

	constructor(
		/** @internal */
		readonly dialect: MySqlDialect,
		/** @internal */
		readonly session: MySqlSession<any, any, any, any>,
		schema: RelationalSchemaConfig<TSchema> | undefined,
		protected readonly mode: Mode,
	) {
		this._ = schema
			? {
				schema: schema.schema,
				fullSchema: schema.fullSchema as TFullSchema,
				tableNamesMap: schema.tableNamesMap,
			}
			: {
				schema: undefined,
				fullSchema: {} as TFullSchema,
				tableNamesMap: {},
			};
		this.query = {} as typeof this['query'];
		if (this._.schema) {
			for (const [tableName, columns] of Object.entries(this._.schema)) {
				(this.query as MySqlDatabase<TQueryResult, TPreparedQueryHKT, Record<string, any>>['query'])[tableName] =
					new RelationalQueryBuilder(
						schema!.fullSchema,
						this._.schema,
						this._.tableNamesMap,
						schema!.fullSchema[tableName] as MySqlTable,
						columns,
						dialect,
						session,
						this.mode,
					);
			}
		}
		this.$cache = { invalidate: async (_params: any) => {} };
	}

	/**
	 * Creates a subquery that defines a temporary named result set as a CTE.
	 *
	 * It is useful for breaking down complex queries into simpler parts and for reusing the result set in subsequent parts of the query.
	 *
	 * See docs: {@link https://orm.drizzle.team/docs/select#with-clause}
	 *
	 * @param alias The alias for the subquery.
	 *
	 * Failure to provide an alias will result in a DrizzleTypeError, preventing the subquery from being referenced in other queries.
	 *
	 * @example
	 *
	 * ```ts
	 * // Create a subquery with alias 'sq' and use it in the select query
	 * const sq = db.$with('sq').as(db.select().from(users).where(eq(users.id, 42)));
	 *
	 * const result = await db.with(sq).select().from(sq);
	 * ```
	 *
	 * To select arbitrary SQL values as fields in a CTE and reference them in other CTEs or in the main query, you need to add aliases to them:
	 *
	 * ```ts