Multi criteria in a query

Hello,

I need to create a query on the ProjTable.

I need to select all project type "contrat" and "Renego" and whoose date is the "limit date SAV". If this dateis not filled, we should take the "end dateRenego".

So i create a methode to init my query :

void InitQuery(query query = null)
{
    QueryBuildDataSource        qbdsProjTable;
    QueryBuildRange             qbrContractType;
    QueryBuildRange             qbrContractRenego;
    QueryBuildRange             qbrSalesType;
    QueryBuildRange             qbDate;

    ;

    query               = new Query();

    qbdsProjTable       = query.addDataSource(tablenum(ProjTable));
    qbrSalesType        = qbdsProjTable.addRange(fieldnum(ProjTable, AVA_SalesType)); // project type "contrat"
    qbrSalesType.value(QueryValue(AVA_SalesTypeEnum::Contract));
    qbrContractRenego  = qbdsProjTable.addRange(fieldnum(ProjTable, AVA_ContratRenego)); // project type "Renego"
    qbrContractRenego.value(QueryValue(NoYes::Yes));

    qbDate = qbdsProjTable.addRange(fieldnum(ProjTable, AVA_ContratDateLimiteRenego)); // the date is the "limit date SAV"
    qbDate.value(QueryRange(dStart, dend)); // dStar & dend came from a dialog

    queryRun    = new SysQueryRun(query);

}

Now i should take AVA_ContratDateFinRenego ("end dateRenego") when AVA_ContratDateLimiteRenego is not filled ?

I hope I wasclear enough (sorry for my poor englishImage may be NSFW.
Clik here to view.)

Thanks