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

includes/database/query.inc, line 948

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) . '} ';
    }
}