SQL multiple filter doesn't work

Question

I recently created a custom component for Joomla! 3.x designed to handle quotes. It's quite simple: I insert various quotes in the database and I want to show them in frontend lists.

I also created a table called "players", because every quote can be associated to one or more players. I did that because I want users to be able to filter the quotes by players, so I put search filters in the frontend lists.

Now, the backend and the frontend lists works well: I'm perfectly able to create a quote and associate it to one on more players, and the quotes are shown correctly in the frontend lists.

The problem is in the search tools. I had a Player filter (it's a SQL field) which let me filter quotes by a player, and it works. But I wanted to let user search by one or more players, so I added "multiple='multiple'" to the xml file. It actually becomes multiple, letting me select more elements, but the search system stops working.

What can I do? I'm sorry for the lack of details, but I'm quite new to Joomla! development and I created the component with an automatic component creator, adjusting it by my needs.

Thank you all.

Answer 1

If you have added multiple='multiple' then the form is getting an array of values (instead of a scalar value).

These array of values has to be translated in the SQL query to a statement like this one:

SELECT ... FROM #__Players WHERE xxx IN (a,b,c,d)

Check how the form is being applied in the query. For instance, SELECT statement can be created in this way:

        $query = $db->getQuery(true)
            ->select('*')
            ->from('#__Players')
            ->where('xxx IN (' . implode(',', $pks) . ')');