使用PHP从数据库打印数据[重复]

Question

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• mysql_fetch_array()/mysql_fetch_assoc()/mysql_fetch_row()/mysql_num_rows etc… expects parameter 1 to be resource or result 32 answers

Everyone says printing data from a MySQL database is easy but so far I'm stumped. I am new to PHP, and am trying to print out an individuals data from a database. So for example Joe Bloggs has logged in, and then he can view what his hobbies are etc. So what I am trying to achieve is getting a user to log in and see THEIR info.

Basically, the user can log in, however I tried to set a up variable to store the SQL query and then print it out if the user logged in successfully, however I now get the following error message- that will no go away.

( ! ) 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

Like virtually all beginners I have made the mistake of creating a massive file that overcomplicates what am trying to code,(it is also very late a night and I'm tired hence why I might not be able to see any errors). However it is well commented

I would appreciate any comments and suggestions!!

// 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

Answer 1

Heres are some of basics step that may help you if your a beginner in using php and mysql depends on what connection you are suitable to use..

MYSQLI :

FIRST : SET UP CONFIGURATION FOR DATABASE USER,PASS,HOST,DBNAME

$conn = new mysqli('database_server','database_username','database_password','database_name');

SECOND : Create a Query(you may insert your query here)..

$result= $conn->query("SELECT SUM(Total_Steps) AS value_sum FROM users");

FINAL : SHOWN RECORDS USING MYSQL FUNCTIONS LIKE..

while($row = $result->fetch_assoc()){
    echo $row['dabatase_columnname'];
    echo $row['database_columnname'];
}

PDO :

Connect to Database db = new PDO("...");

Create a Query

$statement = $db->prepare("select id from some_table where name = :name");

Execute query with the bind paramater

$statement->execute(array(':name' => "Jimbo"));

Fetch all data return by query

$row = $statement->fetch(); // Use fetchAll() if you want all results, or just iterate over the statement, since it implements Iterator

MYSQL :

FIRST : SET UP CONFIGURATION FOR DATABASE USER,PASS,HOST,DBNAME

$conn = mysql_connect('database_server','database_username','database_password');
mysql_select_db($conn,'databasename')

SECOND : Create a Query(you may insert your query here)..

$result= mysql_query("SELECT SUM(Total_Steps) AS value_sum FROM users");

FINAL : SHOWN RECORDS USING MYSQL FUNCTIONS LIKE..

while($row = $result->mysql_fetch_array($result)){
    echo $row['dabatase_columnname'];
    echo $row['database_columnname'];
}