每个人都说从MySQL数据库打印数据很容易，但到目前为止，我很难过。我是PHP的新手，我正在尝试从数据库中打印出个人数据。所以例如Joe Bloggs已经登录，然后他可以查看他的爱好是什么等等。所以我想要实现的是让用户登录并查看他们的信息。
基本上，用户可以登录，但是我尝试设置一个up变量来存储SQL查询，然后在用户成功登录时将其打印出来，但是我现在收到以下错误消息 - 这不会消失
( ! ) SCREAM: Error suppression ignored for
( ! ) Warning: mysql_fetch_array() expects parameter 1 to be resource, string given in C:\wamp\www\myfiles\login.inc.php on line 32
Call Stack
# Time Memory Function Location
1 0.0015 365584 {main}( ) ..\index.php:0
2 1.0144 387472 include( 'C:\wamp\www\myfiles\login.inc.php' ) ..\index.php:6
3 1.0427 390752 mysql_fetch_array ( ) ..\login.inc.php:32
与几乎所有的初学者一样，我犯了一个错误，就是创建了一个过于复杂的代码的大型文件，（这也是很晚的一个晚上，我很累，因此我可能无法看到任何错误） 。不过评论很好
我将不胜感激任何意见和建议!!
// create variables username and password,if a user doesn't enter a UN and PW send error message
if (isset($_POST['username'])&& isset ($_POST['password'])){
$username= $_POST['username'];
$password= $_POST['password'];
if (empty ($username)&&empty ($password)){
echo 'supply username and password';
}
// save our MySQl queries as variables in order to reference them later on
// for login
$query = "SELECT * FROM `students` WHERE `username`='$username'AND `password`='$password'";
// user login result
$result= mysql_query($query);
// display the courses that user is taking
$user= "SELECT * FROM `students`";
// set conditions for login
if($result) {
// if the data matches by rows send a message saying the user has logged in
if(mysql_num_rows($result) > 0) {
session_regenerate_id();
$member = mysql_fetch_assoc($result);
$_SESSION['SURNAME_NAME'] = $member['username'];
$_SESSION['SESS_ID'] = $member['password'];
session_write_close();
//if logged on list course they are studying
echo 'you are now logged in.<a href = "logout.inc.php">Log out</a>';
while($row = mysql_fetch_array($user))
{
echo $row['GivenName'],$row['username'], $row['password'],$row['Course1'],$row['Course2'], $row['Course2'];
echo "<br />";
}
exit();
}else {
// create boolean condition- if no match send error message
$errflag = true;
if($errflag) {
session_write_close();
echo 'invalid username/password combination';
exit();
}
}
}else {
// display errors
echo mysql_errno() . ": " . mysql_error(); exit();
}
}
?>
<form method="POST">
Username: <input type = "text" name="username"> Password: <input type ="password" name="password">
<input type="submit" value="Log in">
</form
答案 0 :(得分：2)
如果您的初学者使用php和mysql取决于您适合使用的连接，那么继承人是一些基本步骤可能对您有所帮助..
MYSQLI ：
首先：为数据库用户，PASS，HOST，DBNAME设置配置
$conn = new mysqli('database_server','database_username','database_password','database_name');
SECOND：创建查询（您可以在此处插入查询）..
$result= $conn->query("SELECT SUM(Total_Steps) AS value_sum FROM users");
最终：使用MYSQL函数显示记录...
while($row = $result->fetch_assoc()){
echo $row['dabatase_columnname'];
echo $row['database_columnname'];
}
PDO ：
连接数据库 db = new PDO（“...”）;
创建查询
$statement = $db->prepare("select id from some_table where name = :name");
使用绑定参数执行查询
$ statement-＆gt; execute（array（'：name'=＆gt;“Jimbo”））;
获取所有按查询返回的数据
$row = $statement->fetch(); // Use fetchAll() if you want all results, or just iterate over the statement, since it implements Iterator
MYSQL ：
首先：为数据库用户，PASS，HOST，DBNAME设置配置
$conn = mysql_connect('database_server','database_username','database_password');
mysql_select_db($conn,'databasename')
SECOND：创建查询（您可以在此处插入查询）..
$result= mysql_query("SELECT SUM(Total_Steps) AS value_sum FROM users");
最终：使用MYSQL函数显示记录...
while($row = $result->mysql_fetch_array($result)){
echo $row['dabatase_columnname'];
echo $row['database_columnname'];
}
答案 1 :(得分：0)
问题是你没有这样做：
mysql_query($user);
只需在mysql_fetch_array之前添加：
$user_result = mysql_query($user);
while($row = mysql_fetch_array($user_result)){
//...
}
但是，正如另一个人所说，请改用MySqli或PDO。
答案 2 :(得分：0)
如上所述，avoid using mysql_* functions in new code。它们不再维护，并且已被正式弃用。
以下是使用PDO和预准备语句的代码示例。您可能只需要更改连接信息。
<?php
// Get your connection sorted.
$db = new PDO('mysql:host=localhost;dbname=testdb;charset=utf8', 'username', 'password');
// Prepare a few statements for use later.
$stmtResult = $db->prepare("SELECT * FROM `students` WHERE `username`=?AND `password`=?");
$stmtUser = $db->prepare("SELECT * FROM `students`");
// create variables username and password,if a user doesn't enter a UN and PW send error message
if (isset($_POST['username'])&& isset ($_POST['password'])){
$username= $_POST['username'];
$password= $_POST['password'];
if (empty ($username)&&empty ($password)){
echo 'supply username and password';
}
// Use the try catch paradigm instead of if/else, because PDO will
// throw an exception if things go sideways.
try{
// Execute the prepared statement, passing in the variables.
$stmtResult->execute(array($username, $password));
// Get the results in an array & then get the result count.
$rows = $stmtResult->fetchAll(PDO::FETCH_ASSOC);
$row_count = $stmt->rowCount()
if($row_count > 0) {
session_regenerate_id();
$member = $rows[0];
$_SESSION['SURNAME_NAME'] = $member['username'];
$_SESSION['SESS_ID'] = $member['password'];
session_write_close();
//if logged on list course they are studying
echo 'you are now logged in.<a href = "logout.inc.php">Log out</a>';
$stmtUser->execute();
// I moved this next call down to the loop because
// there is no real reason to call it sooner than this
while($row = $stmtResult->fetchAll(PDO::FETCH_ASSOC))
{
echo $row['GivenName'],$row['username'], $row['password'],$row['Course1'],$row['Course2'], $row['Course2'];
echo "<br />";
}
exit();
}else {
// create boolean condition- if no match send error message
$errflag = true;
if($errflag) {
session_write_close();
echo 'invalid username/password combination';
exit();
}
}
}catch(PDOException $ex) {
// This is what happens if something did go sideways.
echo $ex->getCode() . ": " . $ex->getMessage();
exit();
}
}
?>
<form method="POST">
Username: <input type = "text" name="username"> Password: <input type ="password" name="password">
<input type="submit" value="Log in">
</form