SELECT 在 PL/pgSQL 函数中引发异常

Question

我想在一个函数内实现一个循环，但我收到这个错误：

ERROR query has no destination for result data

代码：

CREATE OR REPLACE FUNCTION  my_function(ill int, ndx_ bigint) RETURNS int AS
$$
DECLARE
    found_id int;
BEGIN
    FOR found_id IN 1..25 LOOP
        SELECT 1;
    END LOOP;
    RETURN 1;
END;
$$ LANGUAGE plpgsql;

SELECT my_function( 0,79 );

为什么？如何解决？

Answer 1

The manual instructs:

Sometimes it is useful to evaluate an expression or SELECT query but discard the result, for example when calling a function that has side-effects but no useful result value. To do this in PL/pgSQL, use the PERFORM statement:
PERFORM query;

除非您分配结果，否则替换

SELECT 1;

和

PERFORM 1;

SELECT 在 PL/pgSQL 函数中引发异常

SELECT raises exception in PL/pgSQL function

postgresql

plpgsql