Regards Rafael

->columns(‘COUNT(1)’);

Thanks again.

what is the practical importance of Zend_Db_Select::columns()? Does it have a connection to the topic of this article?

Passing a null $name to Zend_Db_Select::from() seemed to be the only way to re-specify the column selection for an existing “from” clause.

As soon as 1.6 goes stable, I’ll check it out and update this post with any changes.

Unfortunately, I haven’t been able to use the code as-is, I was getting “Select query cannot join with another table” PDO exception.

I had to extend Zend_Db_Table_Select and add a method to custom set $_parts[] property:

class MySite_Db_Table_Select extends Zend_Db_Table_Select
{
public function setPart($correlation, $part, $col)
{
array_push($this->_parts[$part], array($correlation, $col, null));
}
}

And:

$select->reset(Zend_Db_Select::LIMIT_COUNT)
->reset(Zend_Db_Select::LIMIT_OFFSET)
->reset(Zend_Db_Select::ORDER)
->reset(Zend_Db_Select::COLUMNS)
->setPart($this->_name, Zend_Db_Select::COLUMNS, new Zend_Db_Expr(‘COUNT(1)’));

Any idea why your code wasn’t working? I am using ZF v1.6RC1.

It looks like the problem lies in null argument of

->from(null, ‘COUNT(1)’);

Setting NULL creates problem in Zend\Db\Table\Select.php -> assemble() method:

foreach ($fields as $columnEntry) {

/**
* $columnEntry is: array(false, Zend_Db_Expr(‘COUNT(1)’), false). First ‘false’ is
* the result of passing NULL to $select->from().
*/
list($table, $column) = $columnEntry;

if ($column) {
if (!isset($from[$table]) || $from[$table]['tableName'] != $primary) {
// We end up here because list() above sets $table to NULL.
throw new Zend_Db_Table_Select_Exception(‘Select query cannot join with another table’);
}
}
}

Now, passing the same table name to $select->from() as:

->from(‘myTable’, ‘COUNT(1)’);

or

->from($this->_name, ‘COUNT(1)’);

creates a second element in $select->_parts['from'] with a new correlation name “myTable_2″. This forces Zend_Db to join the same table again (using “myTable_2″ alias) and that causes PDO exception saying that field name is ambiguous.

I am really curious to know how all that works for you. Maybe we could figure out correct way of doing it.

What’s your ZF version?

Thanks