How can I call an oracle function as part of a parameterized query?

I have a number of automatically generated data access classes to handle things like inserts & updates.

These look like:

cmd.CommandType = CommandType.Text
cmd.CommandText =  "UPDATE myTable set f1 = :f1, f2 = :f2, f3 = :f3 where id = :id"

cmd.Parameters.AddWithValue("开发者_JS百科:f1", _f1)
cmd.Parameters.AddWithValue(":f2", _f2)
cmd.Parameters.AddWithValue(":f3", _f3)
cmd.ExecuteNonQuery()

If I were to re-write the sql to do what I want, it would look something like

cmd.CommandText =  "UPDATE myTable set f1 = pkg.getMyValue, f2 = :f2, f3 = :f3 where id = :id"

Is there any way to do this by setting _f1 to a "special" value, without changing the update SQL or the way the parameters are set? Only in certain cases will I need to set the value of f1 - most of the time, it will be null.

Using .net 2.0, and system.data.oracleclient against oracle 11.

No, you can't. A bind variable is a literal, you can't specify a package to be executed.

You might consider a trigger on the underlying table that fills f1 with pkg.getMyValue if it is null:

create or replace trigger myTrigger
before insert or update on myTable for each row
begin
  if :new.f1 is null
  then 
    :new.f1 := pkg.getMyValue;
  end if;
end;
/