delete from B where B.key1 in(select B.key1 from B,A where B.key1=A.key1 and B.key2=A.key2)
and B.key2 in (select B.key2 from B,A where B.key1=A.key1 and B.key2=A.key2)
insert into #A values('aaa')
insert into #A values('bbb')
insert into #A values('ccc')
insert into #B values('aaa')
insert into #B values('bbb')
insert into #B values('ddd')
delete from #B where key2 in (select key2 from #A,#B where #A.key1=#B.key2)