Question

如果我想在select查询的where子句中的某些条件下更改逻辑运算符AND，那该怎么办。

例如

select * from table t where t.column='something' AND t.column='something'

select * from table t where t.column='something' OR t.column='something'

我尝试了什么：

select * from table t where t.column='something' 
case some_variable 
when  some_variable='' THEN OR
ELSE AND
END
t.column='something'

但它会在case子句附近引发语法错误。请指教。

编辑：示例小提琴fiddle

Answer 1

以下已成功运作。

select
DISTINCT

`car_detail`.`car_detail_id` as "Car ID.",
`car_detail`.`status` as "Status"

FROM 
`car_detail`

LEFT JOIN `car_reservation_detail` ON car_reservation_detail.car_detail_id=car_detail.car_detail_id


WHERE
(case when car_status='' then (car_detail.status='active' OR car_detail.status='reserved') OR (`car_reservation_detail`.employee_detail_id = emp_id AND     (`car_detail`.`status` = 'sold' or `car_detail`.`status` = 'sure'))
 else 
  (`car_reservation_detail`.employee_detail_id = emp_id AND     `car_detail`.`status` = car_status AND `car_reservation_detail`.`status`='active')
 end)
;

DBfiddle

替换mysql where where

1 个答案: