CROSS JOIN替代方案

Question

我已经有了结果集，但我对具有相同结果的替代查询感兴趣。它们之间可能更好还是更快？

insert into [dbo].[Teams]  values(1,'First')
insert into [dbo].[Teams]  values(2,'Second')
insert into [dbo].[Teams]  values(3,'Third')
insert into [dbo].[Teams]  values(4,'Fourth')
insert into [dbo].[Teams]  values(5,'Fifth')

CREATE TABLE [dbo].[Team_team] (
[id1] [int] NOT NULL,
[id2] [int] NOT NULL
) ON [PRIMARY]
GO

select * from teams;

select t1.id,t2.id  from teams t2 cross join teams t1 

Answer 1

这与其他语法相同：

select t1.id,t2.id  from teams t1, teams t2

不会有性能差异。