sql语句怎么实现动态条件

Question

select * from T where operator = (case when @type = 0 then @o1 else is not null end) 主要是想根据@type 用不同的条件当@type = 0 时 operator = @o 否则 operator is not null 请问各位大侠SQL语句怎么写，最好不要用字符串拼接

Answer 1

select * from T where (operator = @o1 and @type = 0 ) or ( @type <> 0 and operator is not null )

Answer 2

定义一个临时变量，然后用if else去判断，然后把值放到sql语句里面执行

Answer 3

(case when @type=0 then (case when operator=@o then 1 else 0 end) else (case when operator is not null then 1 else 0 end) end )=1