Question

This code works for me very well:

if (someStr == null)
  da.InsertCommand.Parameters.Add("@SOMESTR", SqlDbType.NVarChar).Value = DBNull.Value;
else
  da.InsertCommand.Parameters.Add("@SOMESTR", SqlDbType.NVarChar).Value = someStr;

But my intuition tells me that there may be a one-liner version of it. Something like:

  da.InsertCommand.Parameters.Add("@SOMESTR", SqlDbType.NVarChar).Value = someStr==null ? DBNull.Value : someStr ;

But the one-liner I just posted above fails of course because DBNull.Value doesn’t cast to String.

Is there a way to accomplish the one liner I so desire?

Answer 1

You could cast someStr to an object

For example:

da.InsertCommand.Parameters.Add("@SOMESTR", SqlDbType.NVarChar).Value = someStr==null ? DBNull.Value : (object)someStr;

Or you could do as Oded and Servy suggested and use an extension method. While it may add a few lines of code it will save you from duplicate code.

As Servy pointed out, putting it on object could lead to clutter. For this reason I would put it on SqlParameter

public static void SetValue(this SqlParameter parameter, object value)
{
    parameter.Value = value == null ? DBNull.Value : value;
}

Then use it like so

da.InsertCommand.Parameters.Add("@SOMESTR", SqlDbType.NVarChar).SetValue(someStr);