发布网友 发布时间:2022-05-03 16:14
共2个回答
懂视网 时间:2022-05-03 20:35
SQL 多条件查询
以后我们做多条件查询,一种是排列结合,另一种是动态拼接SQL
如:我们要有两个条件,一个日期@addDate,一个是@name
第一种写法是
if (@addDate is not null) and (@name <> ') select * from table where addDate = @addDate and name = @name else if (@addDate is not null) and (@name =') select * from table where addDate = @addDate else if(@addDate is null) and (@name <> ') select * from table where and name = @name else if(@addDate is null) and (@name = ') select * from table
第二种就是动态组成SQL,通过exec来执行,我就不写,
昨天我想到一种办法
select * from table where (addDate = @addDate or @addDate is null) and (name = @name or @name = ')
结果一调试,成功,
一点想法,有更好方法的,请指教!~
感谢阅读,希望能帮助到大家,谢谢大家对本站的支持!
热心网友 时间:2022-05-03 17:43
方法一,分别查询出来,结果再关联
select fnum1,fnum2 from方法二
select sum(case when a = 2 and b = 3 then 1 else 0 end) as fnum1,有问题请追问