LEFT JOIN连接多表的例子

LEFT JOIN 连接多表的例子

SELECT a.IP as IP, a.hostName as hostname, b.SystemTypeId as SystemTypeId,b.os as os,
Mac,a.UserId,c.UserName,d.DeptName, RoomNo, Number, LAddress,a.other FROM
B_EndpInfo a LEFT  JOIN B_SystemType b  ON a.SystemTypeId =  b.SystemTypeId
LEFT  JOIN B_Users c ON a.UserId =  c.UserId
LEFT  JOIN B_DeptInfo d ON c.DeptNo =  d.DeptNo
ORDER BY a.ip