drupal sql 源码解析query.inc 文件

query.inc 文件：

sql语句：

 $this->condition($field);
1707 line

public function condition($field, $value = NULL, $operator = NULL) {
  if (!isset($operator)) {
    if (is_array($value)) {
      $operator = 'IN';
    }
    elseif (!isset($value)) {
      $operator = 'IS NULL';
    }
    else {
      $operator = '=';
    }
  }
  $this->conditions[] = array(
    'field' => $field,
    'value' => $value,
    'operator' => $operator,
  );

  $this->changed = TRUE;

  return $this;
}

这里会放到 $this->conditions[] 中

$operator = $connection->mapConditionOperator($condition['operator']);

mapConditionOperator 函数：

protected function mapConditionOperator($operator) {
  // $specials does not use drupal_static as its value never changes.
  static $specials = array(
    'BETWEEN' => array('delimiter' => ' AND '),
    'IN' => array('delimiter' => ', ', 'prefix' => ' (', 'postfix' => ')'),
    'NOT IN' => array('delimiter' => ', ', 'prefix' => ' (', 'postfix' => ')'),
    'EXISTS' => array('prefix' => ' (', 'postfix' => ')'),
    'NOT EXISTS' => array('prefix' => ' (', 'postfix' => ')'),
    'IS NULL' => array('use_value' => FALSE),
    'IS NOT NULL' => array('use_value' => FALSE),
    // Use backslash for escaping wildcard characters.
    'LIKE' => array('postfix' => " ESCAPE '\\'"),
    'NOT LIKE' => array('postfix' => " ESCAPE '\\'"),
    // These ones are here for performance reasons.
    '=' => array(),
    '<' => array(),
    '>' => array(),
    '>=' => array(),
    '<=' => array(),
  );
  if (isset($specials[$operator])) {
    $return = $specials[$operator];
  }
  else {
    // We need to upper case because PHP index matches are case sensitive but
    // do not need the more expensive drupal_strtoupper because SQL statements are ASCII.
    $operator = strtoupper($operator);
    $return = isset($specials[$operator]) ? $specials[$operator] : array();
  }

  $return += array('operator' => $operator);

  return $return;
这些应该是condition支持的吧