The DbFunctionCall class is very great.

In the help, I found example with sql server (YEAR, MONTH). I tested it and it's really great.

How with Oracle, can I apply a TO_CHAR(:1, 'YYYY') function with DbFunctionCall?

Thanks,

To a field you mean? Could you give a more precise example?

With SQLServer

fields.DefineField( OrderFieldIndex.OrderId, 0, "OrderID" );
fields.DefineField( OrderFieldIndex.OrderDate, 1, "Month" );

fields[1].ExpressionToApply = new DbFunctionCall( "MONTH", new object[] { OrderFields.OrderDate } );

This will create a query like

select orderID, MONTH(orderdate) from xxxx

With Oracle the function to get the month is to_char(date, 'MM').

The select I want is

select orderID, to_char(orderdate, 'MM') from xxxx

...

As I write my post, I answer my question.

Is this code is correct if I want to select month in Oracle ?

fields.DefineField( OrderFieldIndex.OrderId, 0, "OrderID" );
fields.DefineField( OrderFieldIndex.OrderDate, 1, "Month" );

fields[1].ExpressionToApply = new DbFunctionCall( "TO_CHAR", new object[] { OrderFields.OrderDate, "MM" } );

Thanks

Yes