EntLib Way to Bind "Null" Value to Parameter

Question

Hi,

I wish to pass Null Value to the parameter as follow:

_db.AddInParameter(dbCommand, "Id", DBNull.Value, myContactPerson.Id);

I am receiving the following error :

"can not convert "System.DBNull to System.Data.DbType".

I know the meaning of this error.

But i need to supply null value to myContactPerson.Id

How can i achieve this ?

Answer 1

DBType should be passed in that parameter and should match your the dbtype (string, int, etc.) for the table that you are comparing with in your database. You would replace your value field "myContactPerson.Id" with DBNull.Value to always pass the null value.

Answer 2

If myContactPerson.Id isn't an auto-number, then why not just pass 0.

Answer 3

As per ADO.NET, you can pass DBNull to any DbParameter.

The code should be rewritten as:

_db.AddInParameter(dbCommand, "Id", DbType.Int32, DBNull.Value);