protected function AppendIf(QueryBuilder $QueryBuilder, E\IfExpression $Expression)
{
$QueryBuilder->Append('CASE WHEN ');
$this->Append($QueryBuilder, $Expression->GetConditionExpression());
$QueryBuilder->Append(' THEN ');
$this->Append($QueryBuilder, $Expression->GetIfTrueExpression());
$QueryBuilder->Append(' ELSE ');
$this->Append($QueryBuilder, $Expression->GetIfFalseExpression());
$QueryBuilder->Append(' END ');
}