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);
?>

出现错误是（（（！）致命错误：在第6行的C：\ wamp \ www \ TechnologySociety \ logindata.php中调用未定义的函数conn（）））当我调用函数

时

Answer 1

你需要在logindata.php中包含 conn.php

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

您正在调用session_start（）两次，这样会产生另一个错误。

您还应该考虑使用mysqli而不是mysql

Answer 2

你只需要开始会话 - session_start(); doc session_start()根据通过GET或POST请求传递的会话标识符创建会话或恢复当前会话，或通过cookie传递。

也不要忘记包含连接功能.. include_once('conn.php');

Answer 3

--------------- logindata.php ------------ 在logindata.php顶部的这一行

 include_once("conn.php");

Answer 4

更改

function conn{

为：

function conn(){

并在函数结束时返回连接

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");
  return $con;
}

你应该打电话给谁，

$link = conn();
$query = mysql_query($sql, $link);

Answer 5

你错过了

required conn.php

前

conn();

同样在logindata.php中，无需拨打电话

session_start();

因为它已在conn.php中调用，并且在将其包含在required()之后，它将被添加并调用

也在conn.php中添加括号到函数定义

function conn(){

Answer 6

尝试使用logindata.php

的代码

<?php 
require('conn.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);
?>

当我调用包含mysql连接的函数时出错

6 个答案: