Question

I am trying to build a social network using Zend Framework. However, recently I have difficulty in making some complex SQL queries into Zend language. For example:

"SELECT t.plural_name, p.name as users_name, u.ID 
FROM users u, profile p, relationships r, relationship_types t 
WHERE t.ID=r.type 
      AND r.accepted=1 
      AND (r.usera={$user} OR r.userb={$user}) 
      AND IF( r.usera={$user},u.ID=r.userb,u.ID=r.usera) 
      AND p.user_id=u.ID"

How could I execute this query using Zend’s select() object? Thank you very much!

Answer 1

Whenever I have complex queries to deal with, I usually try to run them in MySQL. Once I have found the exact SQL statement, I start to ‘translate’ it to Zend. I seems a bit complex but in the long run, you get to do them in Zend right away. Here is how I break it down.
First figure out what the SQL statement is:

SELECT t.plural_name, p.name as users_name, u.ID 
FROM users u, profile p, relationships r, relationship_types t 
WHERE t.ID=r.type AND r.accepted=1 AND
 (r.usera={$user} OR r.userb={$user}) AND
 IF( r.usera={$user},u.ID=r.userb,u.ID=r.usera) AND
 p.user_id=u.ID

Now, you will want to convert all the relationships to joins. The joins are somewhat scary at the beginning but it’s simply a way to put the table and the criteria on which it joins to another table in one line.

SELECT t.plural_name, p.name AS users_name, u.ID 
FROM users u
INNER JOIN profile AS p ON p.user_id = u.ID
INNER JOIN relationships AS r ON IF(r.usera={$user}, u.ID=r.userb, u.ID=r.usera)
INNER JOIN relationship_types AS t ON t.ID = r.type
WHERE
 (r.usera={$user} OR r.userb={$user}) AND
 r.accepted=1

Now that it is written in a more ‘Zend friendly’ way, you can easily start to convert it to Zend:

$select = $this->select()->setIntegrityCheck(false);
$select->from(array('u'=>'users'), '');
$select->join(array('p'=>'profile'), 'p.user_id = u.ID', '');
$select->join(array('r'=>'relationships'), 'IF(r.usera={$user}, u.ID=r.userb, u.ID=r.usera)', '');
$select->join(array('t'=>'relationship_types'), 't.ID = r.type', '');
$select->columns(array(
  't.plural_name', 
  'users_name'=>'p.name', 
  'u.ID'));
$select->where('r.usera={$user}');
$select->orWhere('r.userb={$user}');
$select->where('r.accepted=1');

And that should do the job.