当我调用包含mysql连接的函数时出错

Question

---------------conn.php-----------------

 <?php 

    session_start(); 

    function conn{

    $hostname = "localhost";
    $userDB = "root";
    $password = "";
    $databaseName = "forum";
$con = mysql_connect($hostname, $userDB, $password) or
            die("failed to connect");
    mysql_select_db($databaseName, $con) or
            die("failed to connect with database");

        }

            ?>

---------------------logindata.php------------

<?php 

session_start();


conn();

$myusername = mysql_real_escape_string($_POST['username']);
$mypassword = mysql_real_escape_string($_POST['password']);
$query = mysql_query("select * from users where username = '" . $myusername . "'  and password = '" . $mypassword . "' ");
if (mysql_num_rows($query) < 1) {

    echo "wrong";
} else {

    $_SESSION['username'] = $myusername;


    $query = mysql_query("select * from users  where username = '" . $myusername . "'  and password = '" . $mypassword . "' ");
    $row = mysql_fetch_assoc($query);
    $_SESSION['id'] = $row['id'];
    $_SESSION['name'] = $row['name'];
    $_SESSION['email'] = $row['email'];

    echo '<meta http-equiv="Refresh" content="0; URL=posts.php" />';
}



mysql_close($con);
?>

---

The error appears is (( ( ! ) Fatal error: Call to undefined function conn() in C:\wamp\www\TechnologySociety\logindata.php on line 6 )) when i call the function

Answer 1

You need to include conn.php in logindata.php

 //logindata.php
    <?php 
    ....
    include("conn.php");
    session_start();

You are calling session_start() twice, so that will generate another error.

You should also look at using mysqli instead of mysql