Codeigniter MY_Model复合主键

Question

I'm working with a base class MY_Model for accessing the database, which contains all the CRUD methods. The model which I'm using is Jens Segers' MY_Model:

https://github.com/jenssegers/CodeIgniter-My-Model

Now, I have a table in my database which contains a composite primary key (article_id and tag_id). Normally, when the primary key contains only an ID for instance, I could just use:

protected $primary_key = "id";

Is there a possibility for a composite primary key, or should I add a column ID to be the only primary key?

Thanks in advance.

Answer 1

Don't sacrifice your database structure because the custom library you are using doesn't support exactly what you need.

There's a work around however:

That library uses CI's database library and uses the $primary_key in the db->where() function.

That function accepts the following argument formats:

$this->db->where('name', $name);
$this->db->where($array);
$this->db->where($where);//$where is a custom MySQL query string

Therefore, you CANNOT set a composite primary key by setting:

$primary_key = array("article_id", "tag_id");

as the library constantly uses the first method of the where() method above.

Instead, just supply methods like get() or insert() (or other) each time with array("article_id" => $article_id, "tag_id => tag_id) .

The database will throw an error if you try and insert anything matching your primary key, so you can deal with that then.