returnType property

Optional if language = "SQL"; required otherwise.

Cannot be set if routine_type = "TABLE_VALUED_FUNCTION". If absent, the return type is inferred from definition_body at query time in each query that references this routine. If present, then the evaluated result will be cast to the specified returned type at query time. For example, for the functions created with the following statements: * CREATE FUNCTION Add(x FLOAT64, y FLOAT64) RETURNS FLOAT64 AS (x + y); * CREATE FUNCTION Increment(x FLOAT64) AS (Add(x, 1)); * CREATE FUNCTION Decrement(x FLOAT64) RETURNS FLOAT64 AS (Add(x, -1)); The return_type is {type_kind: "FLOAT64"} for Add and Decrement, and is absent for Increment (inferred as FLOAT64 at query time). Suppose the function Add is replaced by CREATE OR REPLACE FUNCTION Add(x INT64, y INT64) AS (x + y); Then the inferred return type of Increment is automatically changed to INT64 at query time, while the return type of Decrement remains FLOAT64.