Question

Scenario: My PHP application will always use the date field DD-MM-YYYY. MySQL obviously always stores dates in YYYY-MM-DD

Disclaimer: I know how to manually change the date formats – that is not the question

Question: What is a good, clean, elegant way to ensure that my application always retrives the date in DD-MM-YYYY, and mySQL always receives the date in YYYY-MM-DD to be stored.

i.e. Basically I want to have a single place where the conversion occurs automatically, without me having to call it each and every time I do an SQL query. That way it doesnt matter if I “forget” to do a date_conversion – it will just always happen each and every time….

I’m thinking of some sort of callback somewhere?

(edit) My idea: I currently use the Codeigniter framework. I’m thinking of using MY_Model, using before_get, before_insert and before_update callbacks. In these callbacks, I can go through all the fields using something like this for a SELECT:

// {insert my query here to get records from DB. Then:
$query = $this->db->query();
$fields = $query->field_data(); 
foreach ($fields as $field)
{
      if ($field->type == 'date')
           // do conversion here
}

and do something similar for an UPDATE/INSERT callback. From what I can tell, there is no extra work on the database (because Codeigniter supplies the information in the $query result)

Thoughts?

edit 2: other idea: just do this for each model, and define which fields are date fields, and just apply the change at each callback… yeah… might do that…?

Answer 1

Ok – answer to my own question – in case people search this and find it:

I am using Jamie’s “MY_Model” – https://github.com/jamierumbelow/codeigniter-base-model

Use callbacks on each of your models which have date fields:

    class Fake_model extends MY_Model
    {
        public $before_create = array ('date_convert_to_mysql');
        public $before_update = array ('date_convert_to_mysql');
        public $after_get = array ('date_convert_to_php');

        function __construct()
        {
             parent::__construct();
        }


protected function date_convert_to_mysql($post)
{
    // Now convert the date field(s)
    $post['purchase_date'] = date("Y-m-d", strtotime($post['purchase_date']));
    return $post;        
}

    protected function date_convert_to_php($result)
{
    // Now convert the date field(s)
    $result['purchase_date'] = date("d-m-Y", strtotime($result['purchase_date']));
    return $result;        
}
}

You’ll need to add foreach loops if selecting or adding multiple records. You could make it a generic callback which cycles each variable checking if it is a date – but it seems like alot of overhead. This way you just need to define the date field(s) once for each model