Question

请我尝试在选择计数（*）上获取关联列值。这是我的代码。

$res = mysql_query("select count(*) as total from table where reg = '12' GROUP BY YEAR DESC LIMIT 7");
while($r4 = mysql_fetch_assoc($res)){

            $totalscore = $r4['AVERAGE'];
            $len = $r4['total'];
}

$len返回我的预期值，而AVERAGE列未定义，$totalscore = $r4['AVERAGE']; AVERAGE是我数据库中的一列。如果我的sql语句是count（*）??这是否意味着我无法获取关联列值？任何想法？

Answer 1

您没有在查询中选择average列您可以选择更多列，如下所示：

SELECT  
   COUNT(*) as total,
   `AVERAGE`
   FROM table 
   WHERE reg = '12' 
   GROUP BY YEAR DESC 
   LIMIT 7

在select count（*）语句中获取关联列值

1 个答案: