mysqli_stmt::bind_param()：变量数与准备语句中的参数数不匹配

Question

我想运行多个 mysql 查询（不是同时进行）。我正在使用准备好的语句来这样做。这是我的代码的要点：

    <?php



if(isset($_GET['username'])&&isset($_GET['activationid'])){

require_once("../database/db_connect.php");

$stmt= $mysqli->stmt_init();
$stmt->prepare("Select username FROM users where username= ? AND activationid= ?");
$username=$_GET['username'];
$activationid=$_GET['activationid'];
$stmt->bind_param("ss",$username,$activationid);
$stmt->execute();
$row=$stmt->get_result()->fetch_array(MYSQLI_ASSOC);

if(!strcmp($row['username'],$username)){
    echo 'you are registered successfully';



$stmt->prepare("UPDATE users SET active=yes where username = ?");
$stmt->bind_param("s",$username);
$stmt->execute();







}
}

?>

和db_connect.php是：

<?php 





define('DBHOST','localhost');
define('DBUSER','root');
define('DBPASS','password');
define('DBNAME','Reminder');

    $mysqli= new mysqli(DBHOST,DBUSER,DBPASS,DBNAME) ;
    if($mysqli->connect_error) { 

    echo $mysqli->mysqli_connect_error();

    }
else {
echo "connected successfully";
}




?>

这给了我这个错误：

Warning: mysqli_stmt::bind_param(): Number of variables doesn't match number of parameters in prepared statement in

谁能告诉我我做错了什么？

Answer 1

请输入如下代码并检查：-

//$stmt= $mysqli->stmt_init(); comment this line
$stmt = $mysqli->prepare("Select username FROM users where username= ? AND activationid= ?") or die( $mysqli->error);
$username=$_GET['username'];
$activationid=$_GET['activationid'];
$stmt->bind_param("ss",$userid,$activationid);
$stmt->execute();

第二个也是一样的:-

$stmt = $mysqli->prepare("UPDATE users SET active=yes where username = ?") or die($mysqli->error);
$stmt->bind_param("s",$username);
$stmt->execute();

注意：- 请注意您的变量已正确定义和设置。谢谢。

Answer 2

准备好并绑定之后（以及执行之前），执行

echo $mysqli->error;

没有什么比知道到底发生了什么更重要的了

mysqli_stmt::bind_param()：变量数与准备语句中的参数数不匹配

mysqli_stmt::bind_param(): Number of variables doesn't match number of parameters in prepared statement in

php

mysql

mysqli

prepared-statement