Question

我有以下SQL：

declare @Users table (
  Id int not null primary key clustered (Id),
  [Name] nvarchar(255) not null
);

declare @Skills table (
  SkillId int not null primary key clustered (SkillId)
); 

declare @UserSkills table (
  UserId int not null, 
  SkillId int not null,
    primary key clustered (UserId, SkillId)
); 

insert into @Users
values (1, 'Jonh'), (2, 'Mary');

insert into @Skills
values (148), (149), (304), (305);

insert into @UserSkills
values (1, 149), (1, 305), (2, 148), (2, 149);

select u.Id, u.Name
from @Users as u
inner join @UserSkills as us
on u.Id = us.UserId
where us.SkillId in (149, 305)
group by u.Id, u.Name
having count(*) = 2

我正在按预期获得John用户。

但是在实际代码中，用户有40列。

是否可以使用select / group by来使用所有列，而无需单独枚举所有列？

Answer 1

加入之前：

select u.*
from @Users u join
     (select us.UserId
      from @UserSkills us
      where us.SkillId in (149, 305)
      group by us.UserId
      having count(*) = 2
     ) us
     on u.Id = us.UserId

选择所有具有分组依据的列，而无需单独选择所有列

1 个答案: