dongluan2612 2014-04-13 03:58
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使用PHP从MySQL中选择并回显单个字段

I'm trying to select and echo a single field.

This is my code when I'm trying it

session_start();
$query = "select id from user where username = ".$_SESSION['username'];
$result = mysql_query($query);
$admin_id = mysql_fetch_array($result);
echo $admin_id['id'];

When I run that code, this warning text appears

mysql_fetch_array() expects parameter 1 to be resource, boolean given in ......

How should I do it?

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2条回答 默认 最新

  • dsaob80228 2014-04-13 04:01
    关注

    You should use quotes when you assign values in sql queries .

    $query = "select id from user where username = '{$_SESSION['username']}'";
    

    Or

    $query = "select id from user where username = '" . $_SESSION['username'] . "'";
    

    However, it is not a good practice so you better look forward prepared statements to reduce sql injection vulnerability : http://ru2.php.net/pdo.prepared-statements

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
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