问题2:我想取出这部分数据:

  也是每组根据Id分组后,判断tab_1的某个分组的SkillId是否完整包含tab_2的某个分组的SkillId。这个时候再用分组合并的办法不管用了。
  当然呢,大神们很快发现了使用charindex来实现:
with cte1 as(
select Id, stuff((select ','+ CONVERT(varchar,SkillId) from tab_1 t where t.Id=t1.Id  for xml path('')),1,1,'') as Skills from tab_1 t1
group by Id
),
cte2 as(
select Id, stuff((select ','+ CONVERT(varchar,SkillId) from tab_2 tt where tt.Id=tt1.Id for xml path('')),1,1,'') as Skills from tab_2 tt1
group by Id
)select * from cte1 join cte2 on CHARINDEX(cte2.Skills,cte1.Skills)=1
  以上只是用到了SQL Server的for xml path()列转行,stuff()字符串函数截取以及charindex()字符串函数来比较字符串。
  另外根据@小飞虾、@小不正经提供的思路:
  1.对2各表分别根据主键字段组内排序计算出每组的总数
  2.对结果1的2个表根据关联字段SkillId进行表联接,并根据1中2个表的主键字段进行组内排序,计算出此结果集的每组的总数
  3.将2得出的结果集进行条件运算。如果问题1的要求则用等号计算;如果是问题2的要求则用>=计算。T-SQL如下:
with cte1 as(
select id,SkillId,count(1) over (partition by Id) as count1 from tab_1
),cte2 as(
select id,SkillId,count(1) over (partition by Id) as count2 from tab_2
),cte3 as(
select cte1.Id,cte1.Skillid,count1,cte2.Id as Id2,cte2.SkillId as SkillId2,cte2.count2,
COUNT(1) over (partition by cte1.Id,cte2.Id) as count3
from cte1  full join cte2
on cte1.SkillId=cte2.SkillId
)select Id,SkillId,Id2,SkillId2 from cte3
where count1=count2 and count3=count2
  那么有什么更多的好的办法没有呢?肯定是有的对吧。请各抒己见,在此肯求大伙儿热心指教。不胜感激!