src/ORM/Connect/Database.php
protected function previewWrite($sql)
    {
        // Only preview if previewWrite is set, we are in dev mode, and
        // the query is mutable
        if (isset($_REQUEST['previewwrite'])
            && Director::isDev()
            && $this->connector->isQueryMutable($sql)
        ) {
            // output preview message
            Debug::message("Will execute: $sql");
            return true;
        } else {
            return false;
        }
    }
protected function previewWrite($sql)
    {
        // Only preview if previewWrite is set, we are in dev mode, and
        // the query is mutable
        if (isset($_REQUEST['previewwrite'])
            && Director::isDev()
            && $this->connector->isQueryMutable($sql)
        ) {
            // output preview message
            Debug::message("Will execute: $sql");
            return true;
        } else {
            return false;
        }
    }
protected function previewWrite ( $ sql ) { // Only preview if previewWrite is set, we are in dev mode, and // the query is mutable if ( isset ( $ _REQUEST [ 'previewwrite' ] ) && Director :: isDev ( ) && $ this -> connector -> isQueryMutable ( $ sql ) ) { // output preview message Debug :: message ( "Will execute: $sql" ) ; return true ; } else { return false ; } }
Determines if the query should be previewed, and thus interrupted silently.
If so, this function also displays the query via the debuging system.
Subclasess should respect the results of this call for each query, and not
execute any queries that generate a true response.

@param string $sql The query to be executed
@return boolean Flag indicating that the query was previewed
Determines if the query should be previewed and thus interrupted silently . If so this function also displays the query via the debuging system . Subclasess should respect the results of this call for each query and not execute any queries that generate a true response .