无法将VAR传递给PDO SQL查询

Question

for some reason I can't pass a VAR into a PDO SQL query .

<?php
$hostname = "host";
$username = "username";
$password = "pass";

$score = "B" ;





try {
    $dbh = new PDO("mysql:host=$hostname;dbname='DBNAME'", $username, $password);
    echo "Connected to database"; // check for connection
    $dbh->exec("UPDATE Quiz1 SET '$score' = 1 WHERE Question = 1");  // THIS DOES NOT  
    //$dbh->exec("UPDATE Quiz1 SET B = 1 WHERE Question = 1"); // THIS WORKS
}
catch(PDOException $e)
    {
    echo $e->getMessage();
    }
?>

Answer 1

$dbh->exec("UPDATE Quiz1 SET `$score` = 1 WHERE Question = 1");

如果由于某种原因必须引用表名或列名，那么你必须在MySQL中使用`。

Answer 2

You use the $score variable here as an attribute name and attribute names should not be in quotes. Try this:

$dbh->exec("UPDATE Quiz1 SET $score = 1 WHERE Question = 1");

(I haven't tested.)