A表(ID不是KEY)
-----------------------------------------
ID CD NAME
1 01 A
1 02 B
1 03 C
2 01 D
2 02 EB表
-----------------------------------------
CD ADDRESS
01 AAA
02 BBB
03 CCC
04 DDD结果:----------------------
ID CD ADDRESS
1 01 AAA
1 02 BBB
1 03 CCC
1 04 DDD
2 01 AAA
2 02 BBB
2 03 CCC
2 04 DDD
-----------------------------------------
ID CD NAME
1 01 A
1 02 B
1 03 C
2 01 D
2 02 EB表
-----------------------------------------
CD ADDRESS
01 AAA
02 BBB
03 CCC
04 DDD结果:----------------------
ID CD ADDRESS
1 01 AAA
1 02 BBB
1 03 CCC
1 04 DDD
2 01 AAA
2 02 BBB
2 03 CCC
2 04 DDD
from a,b
where a.id=b.id and a.cd=b.cd
;
from (select distinct ID from A),
B
from (select distinct ID from A) A,
B
from (select distinct id from a)a,b
;
select *
from (select distinct id from a)a,b
;
insert into a
select '1','01','A'
union all select '1','02','B'
union all select '1','03','C'
union all select '2','01','D'
union all select '2','02','E'create table b(cd varchar(10),address varchar(10))
insert into b
select '01','AAA'
union all select '02','BBB'
union all select '03','CCC'
union all select '04','DDD'select *
from (select distinct id from a)a,b /*
id cd address
----------------------------------
1 01 AAA
1 02 BBB
1 03 CCC
1 04 DDD
2 01 AAA
2 02 BBB
2 03 CCC
2 04 DDD
*/
select a.id,b.cd,b.address from (select distinct id from a)a,b
或select distinct a.id,b.cd,b.address from a,b