select a.man_id,man_name,d.sex_name,zw_name,c.money 
 from man as a  
      left join zw as b on a.zw_id=b.zw_id  
      left join zw as c on a.man_id=c.man_id   -- 同時(shí)關(guān)聯(lián)zw字段，通過(guò)表別名區(qū)別開(kāi)
      left join xb as d on c.sex_id=d.sex_id