Question

$stmt = $con->prepare("SELECT t.name, COUNT(*) 
                        FROM team t
                        JOIN member m ON FIND_IN_SET( m.team_id, t.id ) >0
                        GROUP BY t.name
                        LIMIT 0 , 30");
$stmt->execute();
$stmt->setFetchMode(PDO::FETCH_BOUND);
$stmt->bindColumn('count', $count);
$stmt->bindColumn('name', $name);
while ($row = $stmt->fetch()) 
{
     echo "<tr><td>".$name."</td>";                   
    echo "<td>".$count."</td>";
 }

上面的代码检索了2列：name和count(*)。问题在于访问计数列;我得到以下错误。

警告：PDOStatement :: bindColumn（）：SQLSTATE [HY000]：常规错误：未找到列名＆＃39; count＆＃39;在定义的列中;它不会受到约束

我如何绑定到总计数？

Answer 1

使用别名：COUNT(*) as count。

$stmt = $con->prepare("SELECT t.name, COUNT(*) as count
                        FROM team t
                        JOIN member m ON FIND_IN_SET( m.team_id, t.id ) >0
                        GROUP BY t.name
                        LIMIT 0 , 30");

$stmt->execute();
$stmt->setFetchMode(PDO::FETCH_BOUND);
$stmt->bindColumn('count', $count);
$stmt->bindColumn('name', $name);

while ($row = $stmt->fetch()) 
{
    echo "<tr><td>".$name."</td>";                   
    echo "<td>".$count."</td>";
}

Answer 2

您可以指定列号（从1开始），而不是使用具有列名的别名。

$stmt = $con->prepare("SELECT t.name, COUNT(*) 
                        FROM team t
                        JOIN member m ON FIND_IN_SET( m.team_id, t.id ) >0
                        GROUP BY t.name
                        LIMIT 0 , 30");
$stmt->execute();
$stmt->setFetchMode(PDO::FETCH_BOUND);
$stmt->bindColumn(2, $count);
$stmt->bindColumn(1, $name);

如何引用PDO查询中的count（*）列

2 个答案: