Question

我想构造这样的sql条件。我有一辆桌车，它有id_status，id_category和storage_address这样的字段。我需要选择（{2,4}）id_status的车辆，如果id_category = 4我需要检查字段storage_address是否为空或空。我该怎么做？我应该使用sql if语句吗？我需要这样的东西：

select * from car where id_status in (2,4) and if(id_category =
4,storage_address is NOT NULL,'1=1')

Answer 1

试试这个：

SELECT *
FROM car
WHERE id_status in (2,4)
AND IF(
  id_category = 4,
  storage_address IS NOT NULL,
  1
)

简单地说，你不需要字符串'1=1'，只需要一个普通的1作为真值。

或者你可以做到

SELECT *
FROM car
WHERE id_status in (2, 4)
AND (
  id_category != 4
  OR storage_address IS NOT NULL
)

使用if语句mysql的sql构造条件

1 个答案: