Database classes & best practices

PHP
1

Hi, I was just wondering if somebody could help me out or point me in the direction of the answer.

I have just started working with objects in PHP and have noticed that database querys in PHP don’t work the same way as in procedural PHP.

The database classes I have come across tend to use seperate methods for specifying the query and then running it. For example

$query = $this->database->query('QUERY HERE');
$query->execute();

Also the results are usually returned as an object instead of a result variable like i’m used to in procedural PHP.

I’m sure database classes vary depending on who writes them but this seems to be a common way of doing it. I was just wondering what the theory behind this is, why it is done like this and how I can write my own database class using a similar method.

Are there any books or online resources you can recommend to help me get my head around this?

Thanks

2

Separating building the query from executing it allows you to add functionality to the query object.


$query = $this->database->query('SELECT * FROM table WHERE field = :value');
$query->setParameter('value','some value');

$query->executeReturningObject();
$query->executeReturningArray();
$query->executeReturningSingleResult();

Read and understand the PDO section of the PHP manual. Consider PDO to be a reference implementation.

And then if you really want your head to explode, read the Doctrine 2 ORM manual:

13. Doctrine Query Language — Doctrine 2 ORM v2.1 documentation

3

How people structure their database class is usually a question of personal taste.

If you look at the de-facto PHP database class ([fphp]PDO[/fphp]), you can actually choose how you want to get your results back. That link is also a very good place to get started with reading more about database objects.

4

Thanks for the replies, I will start getting to grips with PDO.