Filtering DB result sets

Yii 1.1 General Discussion
1

I basically have an issue that I’m wondering about, first though I will explain my scenario. I have “pages” and associated with each page are multiple “content modules”, stored in a pages and content table with a one to many relationship.

I could simply do everything I need by making a new model every time I need data but if I’m not mistaken this will use another query every time I need a piece of data when I could load a page and all the content in one go.

So my question is, say I have an array of all the content models in $content, ie:




$pagemodel = Pages::model()->findByAttributes(array('pid'=>$pid));

$content = $pagemodel->content;

How can I select an element of that $content array based on one of the properties of one of those instances in the array, I tried:




$content->findByAttributes(array('cid'=>$cid));

but it didn’t work. Is there any way I can filter a database model once it has already been constructed?

2

In your case, $content is simply an array of model, is not an object at all, so you cannot use any method.

You can do something like:


$content= $magemodel->content(array('condition'=>'cid= $cid'))

In onther words, you can pass an array to the function content that will be used for create a CDbCriteria for filtering the result.

3

Ahh, right, thanks, will that execute another query or will that work with the data thats already loaded into the model?

4

It will fire another query, of corse.

If you want to filter all data at once, you have to:


$pagemodel = Pages::model()->find(array('condition'=>"pid= '$pid'", with=>array('content'=>array('condition'=>"cid= $cid'))));

Is a bit more complicated, but maily we are passing the condition to the first find. This will do all in a sigle query

5

Thanks, thats a great help.

Is there any way I can get it to generate an associative array using a database field as the key when it returns an array of results?

The thing is that I know all the content content rows for a page need to be used so it would be more efficient to fetch them all at once, but I don’t know how to access a row specifically from the pre-prepared array of rows based on a field.

Would the best way to do this be to just use a foreach statement to construct an array from the returned database array? Or is there a cleaner way?

6

I have no experience of this stuff, but there is this interesting new feature in documentation.

Try it an let us know if it solves (and how).

7

Thanks, that worked a treat:


$content = $pagemodel->content(array('index'=>'cid'));

Was exactly what I was looking for!

8

Yeah!

Glad to help you!