If I were to do the following:
$pds= $pdo->prepare("SELECT * FROM userinfo WHERE username=:username AND password=:password");
$pds->execute(array(':username' => $username, ':password' => $password));
$row = $pds->fetch(PDO::FETCH_ASSOC);
Do I need to put a try {} for each command executed, or will a try block cover the entire code, with a single catch block?
Thanks!
Do I need to put a try {} for each command executed, or will a try block cover the entire code,
Here goes a set of proper rules right from the real life:
though you can omit the latter one, as PHP has built-in basic handler that works better than one an inexperienced programmer can develop.
only if you're going to handle the error itself is the only half-way correct statement here. What if you want to create a custom Exception for upper levels, meaning levels which can handle the situation? Something like DupKeyException? That's a common task, as PDO will throw only PDOExceptions. Do you wan't upper levels to handle SQL error states, and driver errors? :D! You are a vandal, I can't see much common sense here.what you would need to do for the query you are doing is:
try{
$pds= $pdo->prepare("SELECT * FROM userinfo WHERE username=:username AND password=:password");
$pds->execute(array(':username' => $username, ':password' => $password));
}
catch(PDOException $ex){
die("Failed to run query: " . $ex->getMessage());
//Or Echo, or store in a variable to process if you don't want to die()
}
$row = $pds->fetch(PDO::FETCH_ASSOC);
Hope this helps!
Edit: Also, if you want a bit more separation and readability for building a query you can try creating a query parameter array instead of creating the array directly in the execute() function.
$pds = $pdo->prepare("SELECT * FROM userinfo WHERE username=:username AND password=:password");
$query_params = array(
':username' => $username,
':password' => $password
);
$result = $pds->execute($query_params);
A try block will fail catch the first exception that is generated. Therefore it is quite safe to place all 3 statements in the try section.
You can also use multiple catch blocks so that different exception types can be handled differently such as:
try {
$pds= $pdo->prepare("SELECT * FROM userinfo WHERE username=:username AND password=:password");
$pds->execute(array(':username' => $username, ':password' => $password));
$row = $pds->fetch(PDO::FETCH_ASSOC);
} catch (PDOException $e) {
echo 'A pdo exception happened';
} catch (Exception $e) {
echo 'A different exception happened';
}
This helps ensure you can for example clean up after the issue.
You should definitely study error handling. Also, you should do a little research (at least on stackoverflow) before posting this type of questions.
You can put that code inside a single try block.
try
{
$pds= $pdo->prepare("SELECT * FROM userinfo WHERE username=:username AND password=:password");
$pds->execute(array(':username' => $username, ':password' => $password));
$row = $pds->fetch(PDO::FETCH_ASSOC);
}
catch(Exception $ex)
{
}
You need only to place a try{} block around the all code, and catch it with a single catch{} block.
See the php manual for more information.
As all of the methods will potentially throw the same exception: PDOException it could make sense to wrap each call it is own try/catch block. Yes, this is a good idea if you need to react depending on which method throws the exception and don't to parse the exception's errorInfo and/or errorCode (which will be driver dependend)
