Method fn

packages/db/src/query/builder/index.ts:850–935

* Functional variants of the query builder * These are imperative function that are called for ery row. * Warning: that these cannot be optimized by the query compiler, and may prevent * some type of optimizations being possible. * @example * ```ts * q.fn.select((row) => ({ *

()

   * ```
   */
  get fn() {
    const builder = this
    return {
      /**
       * Select fields using a function that operates on each row
       * Warning: This cannot be optimized by the query compiler
       *
       * @param callback - A function that receives a row and returns the selected value
       * @returns A QueryBuilder with functional selection applied
       *
       * @example
       * ```ts
       * // Functional select (not optimized)
       * query
       *   .from({ users: usersCollection })
       *   .fn.select(row => ({
       *     name: row.users.name.toUpperCase(),
       *     age: row.users.age + 1,
       *   }))
       * ```
       */
      select<TFuncSelectResult>(
        callback: (row: TContext[`schema`]) => TFuncSelectResult,
      ): QueryBuilder<WithResult<TContext, TFuncSelectResult>> {
        return new BaseQueryBuilder({
          ...builder.query,
          select: undefined, // remove the select clause if it exists
          fnSelect: callback,
        }) as any
      },
      /**
       * Filter rows using a function that operates on each row
       * Warning: This cannot be optimized by the query compiler
       *
       * @param callback - A function that receives a row and returns a boolean
       * @returns A QueryBuilder with functional filtering applied
       *
       * @example
       * ```ts
       * // Functional where (not optimized)
       * query
       *   .from({ users: usersCollection })
       *   .fn.where(row => row.users.name.startsWith('A'))
       * ```
       */
      where(
        callback: (row: TContext[`schema`]) => any,
      ): QueryBuilder<TContext> {
        return new BaseQueryBuilder({
          ...builder.query,
          fnWhere: [
            ...(builder.query.fnWhere || []),
            callback as (row: NamespacedRow) => any,
          ],
        })
      },
      /**
       * Filter grouped rows using a function that operates on each aggregated row