Question

美好的一天，我对PHP并不熟悉，当我尝试执行查询时出现此错误。

警告：

警告：mysqli_stmt :: bind_param（）：变量数与预准备语句中的参数数量不匹配第10行/Users/site/userpanel.php

代码：

$query="SELECT SUM(gebruiker_id) AS totalitems FROM inventory WHERE gebruiker_id = 1";
$stmt = $db->prepare($query);
$stmt->bind_param("s", $items);
$stmt->execute();
$result = $stmt->bind_result($col1);

提前致谢！

Answer 1

您必须使用这样的占位符：

$query="SELECT SUM(gebruiker_id) AS totalitems FROM inventory WHERE gebruiker_id = ?";
$stmt = $db->prepare($query);
$stmt->bind_param("s", $items);
$stmt->execute();
$result = $stmt->bind_result($col1);

Answer 2

有时您不需要绑定：

$query="SELECT SUM(gebruiker_id) AS totalitems FROM inventory WHERE gebruiker_id = 1";
$stmt = $db->prepare($query);
//$stmt->bind_param("s", $items);
$stmt->execute();
$result = $stmt->bind_result($col1);

或

$query="SELECT SUM(gebruiker_id) AS totalitems FROM inventory WHERE gebruiker_id = 1";
$stmt = $db->query($query);
$result = $stmt->bind_result($col1);

但如果您尝试将$items绑定到gebruiker_id，请按@rizier123回答。

使用bind_param（）的PHP问题;

2 个答案: