db_select vs dynamic queries (pdo)
<?php
/* dynamic query */
$query = db_select('node', 'n');
$query->join('field_data_field_datum', 'date', 'n.nid = date.entity_id');
$query->condition('n.type', 'calender_item', '=')
->condition('n.uid', $uid, '=')
->fields('n', array('nid', 'title', 'uid'))
->fields('date', array('field_datum_value'))
->range(0, 50)
->orderBy('title', 'ASC');
$result = $query->execute();
/* db query */
$result = db_query('
SELECT n.nid, n.title, n.uid, date.field_datum_value
FROM {node} n
INNER JOIN field_data_field_datum date ON n.nid = date.entity_id
WHERE n.uid = :uid
ORDER BY n.title ASC
LIMIT 50
OFFSET 0',
array(':uid' => $uid)
);
foreach ($result as $row) {
// do stuff
}
?>
Count example:
$count = db_query("SELECT count(nid) FROM {table}")->fetchField();
for PDO:
$query = db_select('node', 'n');
$result = $query->execute()->rowCount();
For quick reference see:
https://www.drupal.org/node/1251174