我有一个来自mysql的表格,我使用下面的代码输出它,$sql="SELECT * FROM $tbl_name WHERE subunit='$subunit' and part='$part' and session='$session' andclass ='$class' order by names asc";while($data = mysql_fetc
想象一下有两列的表(还有更多,但与这个问题无关): `parameter_id` mediumint(8) unsignedDEFAULT NULL,SELECT EAN FROM eTovar WHERE EAN GROUP BY EAN HAVING parameter_id IS NULL
查询中的错误(1054):“having子句”中的未知列