Question

In the following code:

$selectColumns= array('user_id.user_email', // inner join the data from user_id and user_details
                            'user_details.first_name', 
                            'user_details.last_name');
        $result = $handle->select()->from('user_id', $selectColumns)
                                   ->where('user_id.uid=?', $uid)
                                   ->join('user_details', 'user_id.uid = user_details.uid')
                                   ->query(ZEND_DB::FETCH_OBJ);

Zend selects all the columns in the table, not just the requested ones.

How can I select only some?

Answer 1

The problem is in your join() method call:

->join('user_details', 'user_id.uid = user_details.uid')

The optional third argument is columns from this table. If the argument is absent, it defaults to user_details.*.

Note that you added qualified columns from both tables in the from() table, but this has no effect on the default of user_details.*. Sorry, but Zend_Db_Select just isn’t smart enough to keep track of all that.

You can make the join() call add no columns by passing an empty array:

->join('user_details', 'user_id.uid = user_details.uid', array())

The qualified columns you added in the from() call should still be there. To verify this yourself, print the SQL:

print $result . "\n"; // calls __toString() method on Zend_Db_Select object