using database library calls within a helper

[eluser]AF[/eluser]
I am just starting to use CI, and I am getting stuck with this same issue. It may be that I am thinking incorrectly in how to arrange my code.

I have a set of helper functions that deal with adding some functionality to the calendar library. Within those functions, I need to get a difference between two date. This is very easy in mysql, select date_diff. But I have been completely unable to make database calls unless the function is in a model. And if the function is in a model, I cannot use the function in a helper. I can't use $this within a helper function...

I have to be thinking of this incorrectly, any assistance?

[eluser]InsiteFX[/eluser]
Hi AF,

you can do something like this in helpers.

Code:

function your_function
{
   $CI =& get_instance();
   return $CI->your_return_value;
}

Enjoy
InsiteFX

[eluser]AF[/eluser]
Could you give me a little more detail? Here is the code:

function datediff($sdate, $anchor) {
$query="SELECT DATEDIFF('$sdate','$anchor')";
$query =$this->db->query($query);
$row=$query->result_array();


return($row);
}

So, maybe this is a basic question, but what is the & in your case?

And, thank you too.

[eluser]jegbagus[/eluser]
[quote author="AF" date="1251710269"]Could you give me a little more detail? Here is the code:

function datediff($sdate, $anchor) {
$query="SELECT DATEDIFF('$sdate','$anchor')";
$query =$this->db->query($query);
$row=$query->result_array();


return($row);
}

So, maybe this is a basic question, but what is the & in your case?

And, thank you too.[/quote]

hello af, & get_instance suppose to get instance that CI create when you fire a request. your library and everything that you call from load function will be at this instance. the code will be

Code:

function datediff($sdate, $anchor) {
    $CI =& get_instance();
    $query="SELECT DATEDIFF('$sdate','$anchor')";
    $query =$CI->db->query($query);
    $row=$query->result_array();
    
    return($row);
}

but honestly, i think you should place this code at your library.
any other opinion?

[eluser]Boris Strahija[/eluser]
[quote author="AF" date="1251699598"]I am just starting to use CI, and I am getting stuck with this same issue. It may be that I am thinking incorrectly in how to arrange my code.

I have a set of helper functions that deal with adding some functionality to the calendar library. Within those functions, I need to get a difference between two date. This is very easy in mysql, select date_diff. But I have been completely unable to make database calls unless the function is in a model. And if the function is in a model, I cannot use the function in a helper. I can't use $this within a helper function...

I have to be thinking of this incorrectly, any assistance?[/quote]
I think you're doing it the wrong way. Why don't you just make a pure PHP function, without the db call.

[eluser]AF[/eluser]
Ok, That helps. I had thought I would put it in a library earlier, but the functions don't fit nicely into a class, they are more just a variety of different functions.

A pure PHP function call instead of a db call is an option, but it means I rebuild a bunch of wheels in php when I have the functions working and tested in mysql... I do take your point, is there an easy date_diff function in php? I don't know it off hand.

Thanks for your help, I appreciate the knowledge and experience.

[eluser]Boris Strahija[/eluser]
[quote author="AF" date="1251743015"]Ok, That helps. I had thought I would put it in a library earlier, but the functions don't fit nicely into a class, they are more just a variety of different functions.

A pure PHP function call instead of a db call is an option, but it means I rebuild a bunch of wheels in php when I have the functions working and tested in mysql... I do take your point, is there an easy date_diff function in php? I don't know it off hand.

Thanks for your help, I appreciate the knowledge and experience.[/quote]
Just take a look at the CI date helper, and the function timespan().