php - bool(false) 出现在 bind_param() 函数中

Question

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When to use single quotes, double quotes, and backticks in MySQL (13 个回答)

已关闭 6 年前。

我是一名培训开发人员，我在代码中遇到了有关 bind_param() 函数的错误。

这是我的 create_account.php 代码

    <?php

    if(!isset($_POST['username'])||!isset($_POST['email'])||!isset($_POST['password'])){
    die("Data Error");
    }

    if(strlen($_POST['username'])>150){
    die("Username too Long");
    }


    if(!strpos($_POST['email'],"@")){
    die("Invalid Email Address");
    }

    include_once "config.php";
    // congig.php is as follows
    //define("SERVER_NAME","localhost");
    //define("USERNAME","root");
    //define("PASSWORD","");
    //define("DATABASE","mydatabase");

    $conn = new mysqli(SERVER_NAME,USERNAME,PASSWORD,DATABASE);
    if($conn->connect_error){
    die("Connection Error!".$conn->connect_error);
    }

    $username = $_POST['username'];

    // Code Works till here


    $stmt = $conn->prepare("SELECT count(*) FROM 'users' WHERE 'username' = ?");

    $stmt->bind_param("s",$username);
    $stmt->execute();
    $stmt->bind_result($count);
    $stmt->fetch();
    if($count>0){
    die("Username Already Exist");
    }

    $stmt->close();

    $email = $_POST['email'];
    $password = password_hash($_POST['password'],PASSWORD_BCRYPT);

    $stmt2 = $conn->prepare("INSERT INTO 'users' ('username','email','password') VALUES (?,?,?)");

    if (!$stmt) {
    echo "false";
    }
    else {

    $stmt2->bind_param("sss",$username,$email,$password);

    $stmt2->execute();

    }

    $conn->close();

    header("Location ../signup_success.php");

数据库如下

id(自动递增)

用户名(150 个字符)

电子邮件(200 个字符)

密码(150 个字符)

我在两个 bind_paran() 函数上都遇到错误

fatal error :在 boolean 值上调用成员函数bind_param()......

请帮忙

Answer 1

使用 ` 代替 '

改变

$stmt = $conn->prepare("SELECT count(*) FROM 'users' WHERE 'username' = ?");

至

$stmt = $conn->prepare("SELECT count(*) FROM `users` WHERE `username` = ?");

和

$stmt2 = $conn->prepare("INSERT INTO 'users' ('username','email','password') VALUES (?,?,?)");

到

$stmt2 = $conn->prepare("INSERT INTO `users` (`username`,`email`,`password`) VALUES (?,?,?)");