MySQL wrapper as a object var?

[ohdang888]

Is it a normal or standard practice to set an object var to a MySQL wrapper

i.e.

 

$api = new API();

$api->db = new MySQLwrapper();

 

and in the api methods, they call things like

$this->db->query("blah blah blah");

 

Or should the API class inherit from the MySQLwrapper?

 

Thanks

[KevinM1]

The first way is far superior.  Think about it:

 

Is the API a database?  Of course not.  It uses a database, but it isn't one itself.  Inheritance creates is-a relationships, where an object of a child class is an object of the parent class, with just a little bit extra.

 

Always favor composition (objects containing references to other objects) over inheritance.  Unless you're building a family of objects, inheritance will only set you back.

[scootstah]

If the API class inherits the MySQL wrapper, that is to say the API class is a subclass of the MySQL wrapper. I don't think that's what you want.

[ohdang888]

The first way is far superior.  Think about it:

 

Is the API a database?  Of course not.  It uses a database, but it isn't one itself.  Inheritance creates is-a relationships, where an object of a child class is an object of the parent class, with just a little bit extra.

 

Always favor composition (objects containing references to other objects) over inheritance.  Unless you're building a family of objects, inheritance will only set you back.

 

great explanation. thanks!