Question

So, my situation in logics is kind’a bad, and my math is not that good,
so i need your help “building” a query to fetch information from 3 different tables by join query.
my structure is like this:

• Users table : with primary key “ID”
• Campaigns table : with primary key “ID”
• User_Campaign table : with user_id, and campaign_id rows.

I want to pull all the campaigns that doesn’t exist in user_campaign table with the user id X.

my query is for zend framework.
I will appreciate any kind of help, so thanx, and good evening from israel!

my current query:

$q = $this->select()
                ->setIntegrityCheck(false)
                ->from(array('c' => 'campaigns'))
                ->join(array('uc'=> 'user_campaign'), 'uc.campaign_id != c.id AND uc.user_id != 1', array('campaign_id', 'user_id'));

Answer 1

Try this query out, using a left join, and adding a WHERE on the joined table for a valid id being null, will return results that don’t exist on the right side of the join

public function check_access($campaign_id, $user_id) {
    $q = $this->select()
        ->from(array('c' => 'campaigns'))
        ->joinRight(array('uc'=> 'user_campaign'), 'uc.campaign_id = c.id', array('campaign_id', 'user_id'));
        ->where('uc.user_id != ?', $user_id)
        ->where('campaign_id = ?', $campaign_id);

    // User has an entry, return false
    if($this->fetchRow($select))
        return false;

    // User wasn't found, create an entry, and return true
    $this->insert('users_campaigns', array(
        'user_id'       => $user_id,
        'campaign_id'   => $campaign_id
    ));

    return true;
}