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844天前create table author( |
aid char(4), |
aname varchar2(10), |
sex char(1) |
); |
--drop table author; |
create table aword( |
adate date, |
aid char(4) |
); |
--drop table prize_winner; |
insert into author values('1','join','1'); |
insert into author values('2','karl','0'); |
insert into author values('3','foul','0'); |
insert into author values('4','jell','1'); |
insert into aword |
select sysdate,'1' from dual union |
select sysdate-1,'4' from dual; |
select * from aword; |
select * from author where aid not in(select aid from aword); |
select * from author a where not exists( |
select 1 from aword b where b.aid=a.aid); |
select a.* from author a left join aword b on a.aid=b.aid |
where b.aid is null; |
--内连接 |
select * from author inner join aword on author.aid=aword.aid; |
select * from aword inner join author on author.aid=aword.aid; |
--左外连接 |
select * from author left join aword on author.aid=aword.aid; |
select * from aword left join author on author.aid=aword.aid; |
--右外连接 |
select * from author right join aword on author.aid=aword.aid; |
select * from aword right join author on author.aid=aword.aid; |
--完全连接 |
select * from author full join aword on aword.aid=author.aid; |
by: 发表于：2017-09-28 14:46:33 顶(1) | 踩(1) 回复
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