How can I check PDO connection? - php

Question

Here is my code:
<?php
try{
// connect to database and select database
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "spy";
$dbh_conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
$dbh_conn->exec("set names utf8");
$dbh_conn->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
$dbh_conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch (PDOException $e) {
print "Error!: " . $e->getMessage() . "<br/>";
die();
}
?>
My code works as well. But I seen a similar code which checks the connection like this:
if ( !$dbh_conn ){
// Something Went Wrong
} else {
// All Fine
}
Well do I need to this ^ condition? Or using try catch is enough to check db connection?

Answer 1

It depends on what you set for PDO::ATTR_ERRMODE. In your case, it's set as PDO::ERRMODE_EXCEPTION, so an error will throw an Exception.
$dbh_conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
This error mode however is not applied when you connect (i.e., when __constructor() is called in PDO), since a PDOException is always thrown:
PDO::__construct() will always throw a PDOException if the connection fails regardless of which PDO::ATTR_ERRMODE is currently set. Uncaught Exceptions are fatal.
You can read about the different modes here.