Question

我正在尝试在Postgresql中创建一个用户定义的函数：

CREATE FUNCTION get_balance(user_id integer, statuses integer[]) RETURNS INTEGER 
AS $$
select SUM(table1.credit)
from table1

inner join table2
on table2.field1 = table1.id

inner join table3
on table3.field1 = table2.id
where table3.status_id in (statuses); $$

LANGUAGE SQL;

错误是：

ERROR:  operator does not exist: integer = integer[]
LINE 11: where table3.status_id in (statuses); $$

我做错了什么？

Answer 1

此：

table3.status_id in (statuses)

可以简化为例子：

regress=>  SELECT 1 IN (ARRAY[1,2,3]);
ERROR:  operator does not exist: integer = integer[]
LINE 1: SELECT 1 IN (ARRAY[1,2,3]);
                 ^
HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.

...但IN需要一个文字列表，例如：

regress=> SELECT 1 IN (1, 2, 3);

由于你想传递一个数组，你需要使用需要数组输入的= ANY(...)：

regress=> SELECT 1 = ANY (ARRAY[1,2,3]);
 ?column? 
----------
 t
(1 row)

无法创建简单的Postgresql函数

1 个答案: