DB Update with multiple inputs in a loop

[eluser]oneos[/eluser]
This is the query I was attempting to build, which we could just run as such:

This will do what you want, assuming the `id` fields in the two tables are related.

Code:

$sql = 'UPDATE `ft_categories` `cat`, `ft_upload_data` `dat`'
    . 'SET `dat`.`category` = `cat`.`category_name`'
    . 'WHERE `dat`.`id` = `cat`.`id`;';

$query = $this->db->query($sql);

After you've reloaded your categories table, it'll update your data table, setting the category names to eachother where the id's match.