public function TruncateQuery::__toString

Implements PHP magic __toString method to convert the query to a string.

Return value

string The prepared statement.

Overrides Query::__toString

File

drupal/includes/database/query.inc, line 942

Non-specific Database query code. Used by all engines.

Class

TruncateQuery

General class for an abstracted TRUNCATE operation.

Code

public function __toString() {

  // Create a sanitized comment string to prepend to the query.
  $comments = $this->connection
    ->makeComment($this->comments);

  // In most cases, TRUNCATE is not a transaction safe statement as it is a
  // DDL statement which results in an implicit COMMIT. When we are in a
  // transaction, fallback to the slower, but transactional, DELETE.
  // PostgreSQL also locks the entire table for a TRUNCATE strongly reducing
  // the concurrency with other transactions.
  if ($this->connection
    ->inTransaction()) {
    return $comments . 'DELETE FROM {' . $this->connection
      ->escapeTable($this->table) . '}';
  }
  else {
    return $comments . 'TRUNCATE {' . $this->connection
      ->escapeTable($this->table) . '} ';
  }
}