sql 连接

--left join / left outer join 左连接/左外连接(联合查询的结果以左表的数量为主)
select t.id,t.votetitle,v.id,v.ip from votemaster t left join voter v on v.vatenum = t.id
--right join / right outer join 右连接/右外连接(联合查询的结果以右表的数量为主)
select t.id,t.votetitle,v.id,v.ip from votemaster t right join voter v on v.vatenum = t.id
--full join 全连接(二个表中的数据都出来)
select t.id,t.votetitle,v.id,v.ip from votemaster t full join voter v on v.vatenum = t.id
--inner join 内连接(返回字段ID同时存在于表voteMaster 和 voter中的记录)
select t.id,t.votetitle,v.id,v.ip from votemaster t inner join voter v on v.vatenum = t.id

--select * from votemaster
--select * from voter for update