Drupal 7 Database API example

gistfile1.php

$result = db_query(SELECT a.field_1, b.field_2 as second_field, CONCAT('My', 'S', 'QL') as mysql FROM table_1 a LEFT OUTER JOIN table_2 b ON b.id = a.id WHERE a.field_3 >= 25 and a.field_4 = 'this' ORDER BY a.field_5 DESC);

// Would be equivalent to.

$query = db_select('table_1', 'a');

$query->fields('a', array('field_1'))
  ->addExpression("CONCAT('My', 'S', 'QL')", 'mysql')
  ->leftjoin('table_2', 'b', 'b.id = a.id')
  ->addField('b', 'field_2', 'second_field')
  ->condition('a.field_3', 25, ' >=')
  ->condition('a.field_4', 'this')
  ->orderBy('a.field_5', 'DESC');
  
$result = $query->execute();