StringDatabaseStorage::dbStringSelect

protected StringDatabaseStorage::dbStringSelect(array $conditions, array $options = array())

protected function dbStringSelect(array $conditions, array $options = array()) {
  // Start building the query with source table and check whether we need to
  // join the target table too.
  $query = $this->connection->select('locales_source', 's', $this->options)
    ->fields('s');

  // Figure out how to join and translate some options into conditions.
  if (isset($conditions['translated'])) {
    // This is a meta-condition we need to translate into simple ones.
    if ($conditions['translated']) {
      // Select only translated strings.
      $join = 'innerJoin';
    }
    else {
      // Select only untranslated strings.
      $join = 'leftJoin';
      $conditions['translation'] = NULL;
    }
    unset($conditions['translated']);
  }
  else {
    $join = !empty($options['translation']) ? 'leftJoin' : FALSE;
  }

  if ($join) {
    if (isset($conditions['language'])) {
      // If we've got a language condition, we use it for the join.
      $query->$join('locales_target', 't', "t.lid = s.lid AND t.language = :langcode", array(
        ':langcode' => $conditions['language'],
      ));
      unset($conditions['language']);
    }
    else {
      // Since we don't have a language, join with locale id only.
      $query->$join('locales_target', 't', "t.lid = s.lid");
    }
    if (!empty($options['translation'])) {
      // We cannot just add all fields because 'lid' may get null values.
      $query->fields('t', array('language', 'translation', 'customized'));
    }
  }

  // If we have conditions for location's type or name, then we need the
  // location table, for which we add a subquery. We cast any scalar value to
  // array so we can consistently use IN conditions.
  if (isset($conditions['type']) || isset($conditions['name'])) {
    $subquery = $this->connection->select('locales_location', 'l', $this->options)
      ->fields('l', array('sid'));
    foreach (array('type', 'name') as $field) {
      if (isset($conditions[$field])) {
        $subquery->condition('l.' . $field, (array) $conditions[$field], 'IN');
        unset($conditions[$field]);
      }
    }
    $query->condition('s.lid', $subquery, 'IN');
  }

  // Add conditions for both tables.
  foreach ($conditions as $field => $value) {
    $table_alias = $this->dbFieldTable($field);
    $field_alias = $table_alias . '.' . $field;
    if (is_null($value)) {
      $query->isNull($field_alias);
    }
    elseif ($table_alias == 't' && $join === 'leftJoin') {
      // Conditions for target fields when doing an outer join only make
      // sense if we add also OR field IS NULL.
      $query->condition(db_or()
        ->condition($field_alias, (array) $value, 'IN')
        ->isNull($field_alias)
        );
    }
    else {
      $query->condition($field_alias, (array) $value, 'IN');
    }
  }

  // Process other options, string filter, query limit, etc.
  if (!empty($options['filters'])) {
    if (count($options['filters']) > 1) {
      $filter = db_or();
      $query->condition($filter);
    }
    else {
      // If we have a single filter, just add it to the query.
      $filter = $query;
    }
    foreach ($options['filters'] as $field => $string) {
      $filter->condition($this->dbFieldTable($field) . '.' . $field, '%' . db_like($string) . '%', 'LIKE');
    }
  }

  if (!empty($options['pager limit'])) {
    $query = $query->extend('Drupal\Core\Database\Query\PagerSelectExtender')->limit($options['pager limit']);
  }

  return $query;
}