douting0585 2016-10-26 10:40
浏览 21
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从数据库中读取值,echo

Very basic but as a rookie I am struggling. The echo doesnt show any value, just the text. What am I doing wrong?

Connect.php:

<?php
$connection = mysqli_connect('test.com.mysql', 'test_com_systems', 'systems');
if (!$connection){
    die("Database Connection Failed" . mysqli_error($connection));
}
$select_db = mysqli_select_db($connection, 'swaut_com_systems');
if (!$select_db){
    die("Database Selection Failed" . mysqli_error($connection));
}
?>

Get.php:

<?php
    require('connect.php');
        $query2 = "SELECT systemid FROM user WHERE username=test";
        $result2 = mysqli_query($connection, $query2);

    echo ( 'SystemID: '.$result2);

    ?>
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3条回答 默认 最新

  • douwen0647 2016-10-26 10:46
    关注

    Assuming you have connected to the database successfully then the query is incorrect. You must wrap all text values in quotes like this

    <?php
        require('connect.php');
        $query2 = "SELECT systemid FROM user WHERE username='test'";
        $result2 = mysqli_query($connection, $query2);
    

    Now the mysqli_query submits the query to the database where it is run and a result set built. To see the result set you need to read the result set back from the database using one of the fetch functions for example

        $row = mysqli_fetch_assoc($result2);
    
        echo 'SystemID: ' . $row['systemid'];
    

    If there are more than one rows in the result set you must do that in a loop like this

        while ($row = mysqli_fetch_assoc($result2)){
            echo 'SystemID: ' . $row['systemid'];
        }
    
    本回答被题主选为最佳回答 , 对您是否有帮助呢?
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