Return to Answer

Take a look at How to convert sql query to magento in order to fetch data

$read = Mage::getSingleton('core/resource')->getConnection('core_read');

$readresult = $read->query("SELECT id FROM customers_old");

while ($row = $readresult->fetch() ) {
    $Ids[] = $row['id'];
}

See Conquer the 5 Most Common Magento Coding Issues to Optimize Your Site for Performance

Take a look at How to convert sql query to magento in order to fetch data

$read = Mage::getSingleton('core/resource')->getConnection('core_read');

$readresult = $read->query("SELECT id FROM customers_old");

while ($row = $readresult->fetch() ) {
    $Ids[] = $row['id'];
}

See Conquer the 5 Most Common Magento Coding Issues to Optimize Your Site for Performance

Take a look at How to convert sql query to magento in order to fetch data

$read = Mage::getSingleton('core/resource')->getConnection('core_read');

$readresult = $read->query("SELECT id FROM customers_old");

while ($row = $readresult->fetch() ) {
    $Ids[] = $row['id'];
}

Take a look at How to convert sql query to magento in order to fetch data

$read = Mage::getSingleton('core/resource')->getConnection('core_read');

$readresult = $read->query("SELECT id FROM customers_old");

while ($row = $readresult->fetch() ) {
    $Ids[] = $row['id'];
}

See Conquer the 5 Most Common Magento Coding Issues to Optimize Your Site for Performance

Take a look @ How to convert sql query to magento in order to fetch data

$read = Mage::getSingleton('core/resource')->getConnection('core_read');

$readresult=$read->query("SELECT id FROM customers_old");

while ($row = $readresult->fetch() ) {
$Ids[]=$row['id'];
}

Take a look at How to convert sql query to magento in order to fetch data

$read = Mage::getSingleton('core/resource')->getConnection('core_read');

$readresult = $read->query("SELECT id FROM customers_old");

while ($row = $readresult->fetch() ) {
    $Ids[] = $row['id'];
}