C# ASP.Net Parameters.AddWithValue rejecting null value for parameter

Question

I am populating tables using a stored procedure. The table allows a \'null\' for the middle initial of the name, but I\'m getting the following error message:

Answer 1

add the parameter for MiddleInitial also with Null value

public void ProcessForm(string[] InputData)
    {
        string ConnString = System.Configuration.ConfigurationManager.ConnectionStrings["AssociatedBankConnectionString"].ToString();

        SqlConnection conn = new SqlConnection(ConnString);
        SqlCommand cmd = new SqlCommand("uspInsertPersonalAccountApplication", conn);
        cmd.CommandType = CommandType.StoredProcedure;
        cmd.Parameters.AddWithValue("@AccountType", "Savings");
        cmd.Parameters.AddWithValue("@AccountSubType", "Savings");
        cmd.Parameters.AddWithValue("@ExistingCustomer","No");
        cmd.Parameters.AddWithValue("@MiddleInitial",DBNull.Value);
        conn.Open();
        cmd.ExecuteNonQuery();

        conn.Close();
    }

Answer 2

hey you have to set with store procedure

@MiddleInitial varhcar(8) = null

Answer 3

Try to pass in DBNull.Value instead of null.

Answer 4

There are two options here:

Modify you stored procedure and make @MiddleInitial param optional (which is currently not optional that's why error is thrown)

@MiddleInitial nvarchar(10) = NULL

Or add following line to your code:

cmd.Parameters.AddWithValue("@MiddleInitial", null);

Answer 5

I created an extension method to battle this problem. Marcin's suggestion is also worth considering if you can update the stored procedure.

cmd.Parameters.AddString("@MyParamName", myValue);


public static class SQLExtension
{
    public static void AddString(this SqlParameterCollection collection, string parameterName, string value)
    {
        collection.AddWithValue(parameterName, ((object)value) ?? DBNull.Value);
    }
}

Answer 6

You need to declare on everything - even if it's null.

Use DBNull.Value for MiddleInitial.

cmd.Parameters.AddWithValue("@MiddleInitial",DBNull.Value);