create table a (cola int,colb char (1),colc char (2),cold char (3)) create table b (cola int,cole char (1),colf char (2),colg char (3))insert into a (cola,colb,colc,cold) select 1,'x','xx','xxx' union all select 2,'x','xx','xxx' union all select 3,'x','xx','xxx' union all select 4,'x','xx','xxx' insert into b (cola,cole,colf,colg) select 2,'x','xx','xxx' union all select 4,'x','xx','xxx' select isnull (a.cola,b.cola) as cola, isnull (a.colb,'') as colb, isnull (a.colc,'') as colc, isnull (a.cold,'') as cold, isnull (b.cole,'') as cole, isnull (b.colf,'') as colf, isnull (b.colg,'') as colg from a a full join b b on a.cola=b.cola
左连接: select tableA.col a ,col b,col c,cole e,col f,col g from tableA,tableB where tableA.a *= tableB.a
create table b (cola int,cole char (1),colf char (2),colg char (3))insert into a (cola,colb,colc,cold)
select 1,'x','xx','xxx' union all
select 2,'x','xx','xxx' union all
select 3,'x','xx','xxx' union all
select 4,'x','xx','xxx' insert into b (cola,cole,colf,colg)
select 2,'x','xx','xxx' union all
select 4,'x','xx','xxx' select
isnull (a.cola,b.cola) as cola,
isnull (a.colb,'') as colb,
isnull (a.colc,'') as colc,
isnull (a.cold,'') as cold,
isnull (b.cole,'') as cole,
isnull (b.colf,'') as colf,
isnull (b.colg,'') as colg
from a a full join b b
on a.cola=b.cola
select tableA.col a ,col b,col c,cole e,col f,col g
from tableA,tableB
where tableA.a *= tableB.a