MIcrosoft SQL Server WHERE / CASE子句

Question

我有一个where语句，它取决于一个id，并根据id确定下一个确定的位置。 EX：如果ID = 1，则如果ID＆lt;＆gt;，则where语句应该是＆lt; = 3并且b在4和7之间。 1 where语句应为＆lt; = 4且b介于5和7之间。不确定如何执行此操作。尝试了Case条款，但没有运气。

Answer 1

以下是带有数据的tempdb示例表。

-- Just a test
use tempdb;
go

-- Drop table
if object_id('test') > 0
drop table test
go

-- Create table
create table test
(
    id int,
    a int,
    b int
);

-- Add data
insert into test values
(1, 3, 4),
(2, 4, 5),
(1, 4, 4),
(2, 5, 5),
(1, 3, 3),
(2, 4, 4);

-- Full table
select * from test;

以下是使用CASE语句的解决方案。

-- Show the data
select 
    * 
from 
    test
where
  (
    case
        when id = 1 and a <= 3 and b between 4 and 7 then 1
        when id <> 1 and a <= 4 and b between 5 and 7 then 1
        else 0
    end
  ) = 1;

Answer 2

类似的东西：

where
  (id = 1 and a <= 3 and b between 4 and 7) or 
  (id <> 1 and a <= 4 and b between 5 and 7)

Answer 3

根据您的要求，您只需要使用WHERE括号OR语句：

...
WHERE (ID = 1 AND a <= 3 AND b BETWEEN 4 AND 7)
       OR (ID <> 1 AND a<= 4 AND b BETWEEN 5 AND 7)