左外连接去掉重复的数据

[color=brown] select wzfl.*(物质分类),temp.wzbh as sjbh from wzfl left join (select distinct wzbh from sjwz(上架物质) ) as temp on wzfl.bh = temp.wzbh where fbh = ? 遇到问题》》》学习》》》解决问题 [/color]