表A
ID WT NAME
01 20 XXX
02 10 YYY
03 20 ZZZ
表B
name wtname
X1 XY期待返回结果
01 20 XXX X1 XY
02 10 YYY X1 XY
03 20 ZZZ X1 XY 我知道可以用 selcet * ,(selecet name from b) as a1 ,(selecet wtname from b) as a2 from a 这个来实现但觉得嵌套2个子查询效率太低了,有没更好的写法?在线等待。感激不尽!
ID WT NAME
01 20 XXX
02 10 YYY
03 20 ZZZ
表B
name wtname
X1 XY期待返回结果
01 20 XXX X1 XY
02 10 YYY X1 XY
03 20 ZZZ X1 XY 我知道可以用 selcet * ,(selecet name from b) as a1 ,(selecet wtname from b) as a2 from a 这个来实现但觉得嵌套2个子查询效率太低了,有没更好的写法?在线等待。感激不尽!
select * From 表a cross join 表b
if object_id(N'[表B]') is not null drop table [表B]
create table 表A([ID] varchar(4),[WT] int, [NAME] varchar(10))
create table 表B([name] varchar(4),[wtname] varchar(10))
go
insert into 表A
select '01','20','XXX' union all
select '02','10','YYY' union all
select '03','20','ZZZ'insert into 表B
select 'X1','XY'SELECT * FROM [表A],[表B]/*(3 row(s) affected)(1 row(s) affected)
ID WT NAME name wtname
---- ----------- ---------- ---- ----------
01 20 XXX X1 XY
02 10 YYY X1 XY
03 20 ZZZ X1 XY(3 row(s) affected)*/