使用'OR'的CakePHP SQL操作

I am using CakePHP find to retrieve the data. I need to use OR between conditions so i used following query as stated in CakePHP documentation. This works perfectly other times but the problem arises when the field name is same in OR array, Group.arrival_date in this case.

$this->Group->find('all', 
               array('conditions' => array(
                       'OR' => array( 
                          'Group.arrival_date' => 'DATE_ADD(CURDATE(), INTERVAL 30 DAY)',
                          'Group.arrival_date' => 'DATE_ADD(CURDATE(), INTERVAL 7 DAY)'
                       )
                   )
                ));

The SQL it generate is

SELECT `Group`.`id`, `Group`.`rr_no`, `Group`.`package_id`, `Group`.`user_id`, 
`Group`.`group_name`, `Group`.`pax`, `Group`.`agent_id`, `Group`.`staff_id`, 
`Group`.`arrival_date`, `Group`.`departure_date`, `Group`.`status`, `Group`.`slug`, 
`Group`.`book_flight`, `Group`.`allocated_tents`, `Group`.`alert`, `Group`.`alert_seen` 
FROM `groups` AS `Group` WHERE `Group`.`arrival_date` = 'DATE_ADD(CURDATE(), INTERVAL 7 DAY)'

It takes the second condition only. For different field name like:

$this->Group->find('all', 
                array('conditions' => array(                                                                    
                          'OR' => array( 
                            'Group.slug' => 'slug1',
                            'Group.group_name' => 'group1'
                          )
                      )
              ));

The generated SQL is

SELECT `Group`.`id`, `Group`.`rr_no`, `Group`.`package_id`, `Group`.`user_id`, 
`Group`.`group_name`, `Group`.`pax`, `Group`.`agent_id`, `Group`.`staff_id`, 
`Group`.`arrival_date`, `Group`.`departure_date`, `Group`.`status`, `Group`.`slug`, 
`Group`.`book_flight`, `Group`.`allocated_tents`, `Group`.`alert`, `Group`.`alert_seen` 
FROM `groups` AS `Group` WHERE ((`Group`.`slug` = 'slug1') OR (`Group`.`group_name` = 'group1'))

Which is as expected. What am i missing in the first find i used? How can i get the above query work? Any help would be greatly appreciated. I am using CakePHP 2.0.

Try:

$this->Group->find('all', 
               array('conditions' => array(
                       'OR' => array( 
                          array('Group.arrival_date' => 'DATE_ADD(CURDATE(), INTERVAL 30 DAY)'),
                          array('Group.arrival_date' => 'DATE_ADD(CURDATE(), INTERVAL 7 DAY)')
                       )
                   )
                ));

Or you could use IN:

$this->Group->find('all', 
                 array('conditions' => array(
                     'Group.arrival_date' => array('DATE_ADD(CURDATE(), INTERVAL 30 DAY)', 'DATE_ADD(CURDATE(), INTERVAL 7 DAY)')
                  )
              );

For same field, simply put all values you need for OR in an array.

$this->Group->find('all', 
               array('conditions' => array(

                          'Group.arrival_date' => 
          array('DATE_ADD(CURDATE(), INTERVAL 30 DAY)', 'DATE_ADD(CURDATE(), INTERVAL 7 DAY)' )
                   )
                ));