function Merge::__toString

Overrides Merge::__toString

File

core/modules/pgsql/src/Driver/Database/pgsql/Merge.php, line 175

Class

Merge

PostgreSQL implementation of \Drupal\Core\Database\Query\Merge.

Namespace

Code

public function __toString() {
  // A query using the generic emulation is potentially two queries, so it
  // has no string representation. Let the parent implementation throw.
  if (!$this->isNativeMerge()) {
    return parent::__toString();
  }
  // Create a sanitized comment string to prepend to the query.
  $comments = $this->connection
    ->makeComment($this->comments);
  $this->condition
    ->compile($this->connection, $this);
  // MERGE requires a source relation even when merging a single row of
  // literal values, so use a constant single-row subquery. The ON clause
  // then only matches against the merge table.
  $query = $comments . 'MERGE INTO {' . $this->table . '} USING (SELECT 1) AS drupal_merge_source ON (' . $this->condition . ')';
  if ($this->needsUpdate) {
    $update_fields = [];
    // Expressions take priority over literal fields, so we process those
    // first and remove any literal fields that conflict.
    foreach ($this->expressionFields as $field => $data) {
      if ($data['expression'] instanceof SelectInterface) {
        $data['expression']->compile($this->connection, $this);
        $update_fields[] = $this->connection
          ->escapeField($field) . ' = (' . $data['expression'] . ')';
      }
      else {
        $update_fields[] = $this->connection
          ->escapeField($field) . ' = ' . $data['expression'];
      }
    }
    $max_placeholder = 0;
    foreach (array_diff_key($this->updateFields, $this->expressionFields) as $field => $value) {
      $update_fields[] = $this->connection
        ->escapeField($field) . ' = :db_update_placeholder_' . $max_placeholder++;
    }
    $query .= ' WHEN MATCHED THEN UPDATE SET ' . implode(', ', $update_fields);
  }
  $insert_fields = [];
  $values = [];
  $max_placeholder = 0;
  foreach (array_keys($this->insertFields) as $field) {
    $insert_fields[] = $this->connection
      ->escapeField($field);
    $values[] = ':db_insert_placeholder_' . $max_placeholder++;
  }
  foreach ($this->defaultFields as $field) {
    $insert_fields[] = $this->connection
      ->escapeField($field);
    $values[] = 'DEFAULT';
  }
  $query .= ' WHEN NOT MATCHED THEN INSERT (' . implode(', ', $insert_fields) . ') VALUES (' . implode(', ', $values) . ')';
  // The merge_action() function reports whether the row was inserted or
  // updated, which execute() maps to the STATUS_INSERT and STATUS_UPDATE
  // return values.
  return $query . ' RETURNING merge_action()';
}