sqlserver id相同的多行合并为一行，用逗号分隔

单表操作

创建测试表city：

把cityLevel相同的cityName合并在一起用逗号分隔 如：北京,上海,广州

SELECT cityLevel,
cityName =stuff(
(select ','+cityName FROM city WHERE cityLevel = c.cityLevel for xml path(''))
,1,1,'')
FROM city c
group by cityLevel

用city表和一张新的city命名为c,匹配cityLevel相同的项目,然后用cityLevel进行分组

两表操作

将city表拆开

citys:

city:

SELECT temp2.cityLevel,
cityName =stuff(
(select ','+cityName FROM 
(select cs.cityLevel,cs.cityId,c.cityName from citys as cs inner join city as c on cs.cityId = c.id) temp
WHERE temp.cityLevel = temp2.cityLevel for xml path(''))
,1,1,'')
FROM (select cs.cityLevel,cs.cityId,c.cityName from citys as cs inner join city as c on cs.cityId = c.id) temp2
group by temp2.cityLevel