sql语法,如果存在

Question

为什么我得到错误:

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'IF EXISTS(SELECT id FROM mytable WHERE id = '1')' at line 1 

查询:

IF EXISTS(SELECT id FROM mytable WHERE id = '1')

谢谢

Answer 1

IF EXISTS仅适用于存储过程.在存储过程之外,IF()是一个带有3个参数的函数.适当的用法是

SELECT IF(EXISTS(SELECT `column` FROM `table` WHERE `id` = `1`), 1, 0);