postgresql - PHP and Postgres: catching errors?

Question

How should I prepare the code if it something fails? With try-catch statement or?

function delete_question ( $question_id ) {
    $dbconn = pg_connect("host=localhost port=5432 dbname=heoa user=heoa password=123");

    // removes questions and its dependencies: answers and tags
    $result = pg_query_params ( $dbconn,
        'DELETE FROM questions
        WHERE question_id = $1',
        array ( $question_id )
    );

Answer 1

If you want exceptions, then you need to use PDO.

in case of pg_* functions and your code, you need to check whether $result has the value of false, if it does, then an error occured.

You can get the error description with pg_last_error()

Something like this:

$result = pg_query_params ( $dbconn,
        'DELETE FROM questions
        WHERE question_id = $1',
        array ( $question_id )
    );


if ($result === false) {
    print pg_last_error($dbconn);
} else {
    print 'everything was ok';
}

So, basically, every time you use a pg_* function, you need to check whether false was returned, that's just the way it is with those functions.

Yes, you can build your own wrappers so instead of pg_query* you call my_db_query(), which then does the return value checking and exception throwing.

Or, you could go with PDO, which is able to throw you PDOException for all the errors that can occour.