How to view query error in PDO PHP

Question

try {
    $db = new PDO("mysql:host=".HOST.";dbname=".DB, USER, PW);
    $st = $db->prepare("SELECT * FROM c6ode");
}
catch (PDOException $e){
    echo $e->getMessage();
}

How can I check the mysql error for the query in above case?

Answer 1

You need to set the error mode attribute PDO::ATTR_ERRMODE to PDO::ERRMODE_EXCEPTION.
And since you expect the exception to be thrown by the prepare() method you should disable the PDO::ATTR_EMULATE_PREPARES* feature. Otherwise the MySQL server doesn't "see" the statement until it's executed.

<?php
try {
    $pdo = new PDO('mysql:host=localhost;dbname=test;charset=utf8', 'localonly', 'localonly');
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    $pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);


    $pdo->prepare('INSERT INTO DoesNotExist (x) VALUES (?)');
}
catch(Exception $e) {
    echo 'Exception -> ';
    var_dump($e->getMessage());
}

prints (in my case)

Exception -> string(91) "SQLSTATE[42S02]: Base table or view not found: 
1146 Table 'test.doesnotexist' doesn't exist"

see http://wezfurlong.org/blog/2006/apr/using-pdo-mysql/
EMULATE_PREPARES=true seems to be the default setting for the pdo_mysql driver right now. The query cache thing has been fixed/change since then and with the mysqlnd driver I hadn't problems with EMULATE_PREPARES=false (though I'm only a php hobbyist, don't take my word on it...)

*) and then there's PDO::MYSQL_ATTR_DIRECT_QUERY - I must admit that I don't understand the interaction of those two attributes (yet?), so I set them both, like

$pdo = new PDO('mysql:host=localhost;dbname=test;charset=utf8', 'localonly', 'localonly', array(
    PDO::ATTR_EMULATE_PREPARES=>false,
    PDO::MYSQL_ATTR_DIRECT_QUERY=>false,
    PDO::ATTR_ERRMODE=>PDO::ERRMODE_EXCEPTION
));