作为MySQL SELECT语句的一部分，我正在尝试动态查询数据库。
当前代码：
$stmt = $pdo->prepare('SELECT `COLUMN_NAME` FROM `INFORMATION_SCHEMA`.`COLUMNS` WHERE `TABLE_SCHEMA`="assignment" AND `TABLE_NAME`=:table AND `COLUMN_NAME` != :column1 AND `COLUMN_NAME` != :column2;');
$criteria = [
'table' => $_GET['section'],
'column1' => 'jobid',
'column2' => 'catid'
];
$stmt->execute($criteria);
$arr = array();
echo '<form method="POST">';
foreach ($stmt as $row){
echo '<label>'.ucwords($row['COLUMN_NAME']).':</label>
<input type="text" name="'.$row['COLUMN_NAME'].'"/><p>';
$arr[] = $row;
}
echo '<input type="submit" value="Submit" name="submit"/>
</form>';
if (isset($_POST['submit']))
echo $query = implode(',', $arr);
我使用$_POST值让它工作得很好，但出于某种原因，它输出：
Array,Array,Array,Array,Array
即使$arr的var_dump（）是：
0 =>
array (size=2)
'COLUMN_NAME' => string 'title' (length=5)
0 => string 'title' (length=5)
1 =>
array (size=2)
'COLUMN_NAME' => string 'salary' (length=6)
0 => string 'salary' (length=6)
2 =>
array (size=2)
'COLUMN_NAME' => string 'location' (length=8)
0 => string 'location' (length=8)
3 =>
array (size=2)
'COLUMN_NAME' => string 'description' (length=11)
0 => string 'description' (length=11)
4 =>
array (size=2)
'COLUMN_NAME' => string 'category' (length=8)
0 => string 'category' (length=8)
implode函数不能以您想要的方式处理数组。它获取$arr中的数组，并将它们放入字符串"Array"中。你可以在数组中循环并以这种方式内爆，例如
$list = '';
foreach ($arr as $inner) {
$list .= $inner['COLUMN_NAME'].',';
}
$list = rtrim($list,',');