Question

I’m a newbie when it comes to SQL. When creating a stored procedure with parameters as such:

@executed           bit, @failure            bit, @success            bit, @testID             int,     @time               float = 0, @name               varchar(200) = '', @description        varchar(200) = '', @executionDateTime  nvarchar(max) = '', @message            nvarchar(max) = '' 

This is the correct form for default values in T-SQL? I have tried to use NULL instead of ”.

When I attempted to execute this procedure through C# I get an error referring to the fact that description is expected but not provided. When calling it like this:

        cmd.Parameters['@description'].Value = result.Description; 

result.Description is null. Should this not default to NULL (well ” in my case right now) in SQL?

Here’s the calling command:

        cmd.CommandText = 'EXEC [dbo].insert_test_result @executed,                            @failure, @success, @testID, @time, @name,                             @description, @executionDateTime, @message;';          ...         cmd.Parameters.Add('@description', SqlDbType.VarChar);         cmd.Parameters.Add('@executionDateTime', SqlDbType.VarChar);         cmd.Parameters.Add('@message', SqlDbType.VarChar);          cmd.Parameters['@name'].Value = result.Name;         cmd.Parameters['@description'].Value = result.Description;         ...          try         {             connection.Open();             cmd.ExecuteNonQuery();         }         ...         finally         {             connection.Close();         } 

Answer 1

A better approach would be to change the CommandText to just the name of the SP, and the CommandType to StoredProcedure – then the parameters will work much more cleanly:

cmd.CommandText = 'insert_test_result'; cmd.CommandType = CommandType.StoredProcedure; 

This also allows simpler passing by name, rather than position.

In general, ADO.NET wants DBNull.Value, not null. I just use a handy method that loops over my args and replaces any nulls with DBNull.Value – as simple as (wrapped):

    foreach (IDataParameter param in command.Parameters)     {         if (param.Value == null) param.Value = DBNull.Value;     } 

However! Specifying a value with null is different to letting it assume the default value. If you want it to use the default, don’t include the parameter in the command.