求多表查询问题？？详细点，谢谢各位

select t1.siteid,t1.sitename,t2.boroughname,t3.popedomname,t4.dutyareanme from site t1
left join borough t2 on t1.boroughid=t2.boroguhid
left join popedom t3 on t1.popedomid=t3.popedomid
left join dutyarea t4 on t1.dutyareaid=t4.dutyareaid

另外你可以参考以下连接
http://zhidao.baidu.com/question/9918998.html?si=1