.NET - NULL object if assigned string length is 0

Question

Currently, whenever I pass a string to the db, if that string is empty, then i set that object to NULL by doing the following:

IIf(DescriptionTxt.Text.length > 0, DescriptionTxt.Text, DBNull.Value)

I was thinking about writing a function to reduce the length of this code, and make it more consistent.

However, I was wondering, is there already a way of doing this in .NET 3.5?

Answer 1

Your database will perform better and be easier to query properly if you don't put a bunch of nulls in there. I'd stick with "", 0, -1, negative infinity, or some other value appropriate to your situation and change your application code to suit. Avoid unnecessary nulls in your database.

Answer 2

You could write an extension method:

public static object AsNull(this string me)
{
    if (string.IsNullOrEmpty(me))
        return DBNull.Value;
    return me;
}

Then in code just use

DescriptionTxt.Text.AsNull()

But otherwise there is nothing in .NET that does it by default. In fact, most developers that I know prefer to make a distinction between a NULL and an empty string. They are different in .NET, so it's a lot easier (and consistent) if they are different in the DB as well.

Added: OOps just noticed this is a VB.NET question. Sorry, my VB.NET is a bit rusty, but I'm sure you will be able to translate the simple function above to VB.NET.

Answer 3

You pretty much have the simplest code already. There aren't any 3.5 tools to make this simpler. A refinement might be a merge between your code and @Vilx- code:

IIf(String.IsNullOrEmpty(DescriptionTxt.Text), DBNull.Value, DescriptionTxt.Text)