Mysqli准备语句首先插入然后select语句在stmt中失败 - >执行（）总是无法注册

Question

我试图选择使用 msqli_prepare语句，然后我立即尝试插入记录，如果语句1为真。我确实阅读了很多文章。大部分是人们说我必须先关闭第一个使用第二个声明。但仍然没有用。可能我认为我在错误的地方关闭了stmt。 if ($exec === true)总是假的。请帮忙。 感谢

PHP代码

<?php

require_once("dbcontroller.php");
$db_handle = new DBController();
$conn = $db_handle->connectDB();

if (isset($_POST['btn-register'])) {
    /* Password Matching Validation */
    if ($_POST['password'] != $_POST['confirmpassword']) {
        $message = '<div class="alert alert-danger">Passwords should be same</div>';
    }
    /* Validation to check if Terms and Conditions are accepted */
    if (!isset($message)) {
        if (!isset($_POST["terms"])) {
            $message = '<div class="alert alert-danger">Accept Terms and conditions before submit</div>';
        }
    }

    if (!isset($message)) {

//Function to sanitize values received from the form. Prevents SQL injection
        function clean($conn, $str) {
            $str = @trim($str);
            if (get_magic_quotes_gpc()) {
                $str = stripslashes($str);
            }
            return mysqli_real_escape_string($conn, $str);
        }

        $firstName = clean($conn, $_POST['firstname']);
        $lastName = clean($conn, $_POST['lastname']);
        $mobile = clean($conn, $_POST['mobile']);
        $username = clean($conn, $_POST['username']);
        $email = clean($conn, $_POST['email']);
        $password = clean($conn, md5($_POST['password']));
        $accountHolderName = clean($conn, $_POST['accountHolderName']);
        $bankName = clean($conn, $_POST['bankId']);
        $accountNumber = clean($conn, $_POST['accountNumber']);
        $branchName = clean($conn, $_POST['branchName']);
        $branchCode = clean($conn, $_POST['branchCode']);
        $accountTypeId = clean($conn, $_POST['accountTypeId']);
        $accountactive = 'Y';

        $query = "select USERNAME from USER_DETAILS where USERNAME= ? or EMAIL_ADDRESS = ? ";
        $stmt = $conn->prepare($query);

        $stmt->bind_param("ss", $username, $email);
        $stmt->execute();
        $stmt->store_result();
        $stmt->bind_result($username);
        $stmt->fetch();
        $num_of_rows = $stmt->num_rows;
        $stmt->close();
        if ($num_of_rows == 1) {
            $message = '<div class="alert alert-danger">The username name ' . $username . ' or mail ' . $email . ' is already exist in our database</div>';
        } else {
            $query = "insert into USER_DETAILS(FIRST_NAME,LAST_NAME,MOBILE_NUMBER,USERNAME,
                    EMAIL_ADDRESS,PASSWORD,ACCOUNT_HOLDER,BANK_NAME,ACCOUNT_NUMBER,BRANCH_NAME,BRANCH_CODE,ACCOUNT_TYPE,IS_ACTIVE) values(?,?,
                    ?,?,?,?,?,?,?,?,?,?,?)";
            $stmt1 = $conn->prepare($query);

            $stmt1->bind_param("ssssssssissss", $firstName, $lastName, $mobile, $username, $email, $password, $accountHolderName, $bankName, $accountNumber, $branchName, $branchCode, $accountTypeId, $accountactive);

            $exec = $stmt1->execute();

            if ($exec === true) {
                $message = '<div class="alert alert-success">You have registered successfully!</div>';
            } else {
                $message = '<div class="alert alert-danger">Problem in registration. Try Again!</div>';
            }

            $stmt1->close();
        }
    }
}
$db_handle->closeDB($conn);
?>