DBNULL value question

Using VB.NET, I perform a trim function on a SQL server table field trim(row1(''account'')).

When the field is empty I get an error: cast from 'DBNULL' to String is not valid.

I want to be able to perform that Trim function without testing each single field if it s equal to DBNULL or not.

That s because I have many fields in the same string generated big string and I wanna insert some spaces inside that string:

trim(row1(''account'')) & '' '' & (row1(''address'')) & '' '' & trim(row1(''FirstName'')) & (row1('LastName')).

Thanks a lot

Zath

This is not posible, you can use IIf :

IIf( row1("account") <> DBNull.Value, trim(row1("account")), string.Empty) & IIf( row1("address") <> DBNull.Value, trim(row1("address")), string.Empty)
Vladimir Chtepa

Try calling ToString() on each column like:

trim(row1("account").ToString()) ...

DBNull.ToString() returns an empty string, which shouldn't cause an exception when trim attempts to trim it.

You may just want to create a reusable function that will do most of that for you. This is in C#, but you can create the equivalent in VB:

public string GetString(object item)

{

return item.ToString().Trim();

}

Then you could just do:

GetString(row1("account")) + " " + GetString(row1("address")) + ...

There are other ways to do this as well.

Regards,

Dave
Marco Foco
thanks a lot, works perfectly
DBNULL value question