Table1 存储数据格式结构如下:
Id为主键,CityList为Table2中的CityID
Table2 城市表数据格式如下
正确查询方式
select a.CityID,a.CityName from [Join].dbo.Table2 as a where exists(select * from Table1 where Id=5717 and charindex(','+cast(a.CityID as varchar(max))+',',CityList)>0)
查询结果
红色的 ',' 一定要加上,如果不加查询结果将会有误。
为了代码的规范,在试用 逗号 隔开字符串的存储时,一定要前后都要加','。这样不管在数据处理还是在前段做逻辑判断都比较规范。
以逗号开头,以逗号结尾:charindex(','+cast(a.CityID as varchar(max))+',',CityList)>0
错误的查询方式
1:select a.CityID,a.CityName from [Join].dbo.Table2 as a where exists(select * from Table1 where Id=5717 and charindex(cast(a.CityID as varchar(max)),CityList)>0)
2:select a.CityID,a.CityName from [Join].dbo.Table2 as a where exists(select * from Table1 where Id=5717 and charindex(cast(a.CityID as varchar(max))+',',CityList)>0)
3:select a.CityID,a.CityName from [Join].dbo.Table2 as a where exists(select * from Table1 where Id=5717 and charindex(','+cast(a.CityID as varchar(max)),CityList)>0)