public function viewExists($viewName, $schemaName = null)
{
$view = $this->prepareTable($viewName, $schemaName);
$baseSql = sprintf("SELECT CASE WHEN COUNT(*) > 0 THEN 1 ELSE 0 END RET FROM ALL_VIEWS WHERE VIEW_NAME = %s", Text::upper($view));
if (!empty($schemaName)) {
$schemaName = $this->escapeSchema($schemaName, $this->_escapeChar);
$baseSql .= sprintf("AND OWNER = %s", Text::upper($schemaName));
}
return $baseSql;
}