MySQL函数没有返回任何值

Question

我尝试编写MySql函数来返回一个节点的子计数，并且我写了这段代码

CREATE DEFINER=`root`@`localhost` FUNCTION `get_child_count`(`id` INT) RETURNS int(11)
READS SQL DATA
Begin
declare temp int(11);
SELECT count(*) into temp FROM tbl_photo_album where parent_id = id;
return temp;
End

每当我试图运行这个功能时，它什么都没有。

Answer 1

<可能的选择：代替select ... into...，试试这个：

set temp = (select count(*) from tbl_photo_album where parent_id = id);

Answer 2

尝试这个。

 DELIMITER $$
 CREATE DEFINER=`root`@`localhost` FUNCTION `get_child_count`(`id` INT) RETURNS int(11)
 READS SQL DATA
 Begin
 declare temp int(11);
 SELECT count(*) into temp FROM tbl_photo_album where parent_id = id;
 return temp;
 END$$
DELIMITER ;

select get_child_count(10); --  Pass Id for what you want result.