The parameterized query … expects the parameter '@units', which was not supplied

Question

I\'m getting this exception:

The parameterized query \'(@Name nvarchar(8),@type nvarchar(8),@units nvarchar(4000),@rang\' expects the parameter \'@uni

Answer 1

Here's a way using the null-coalescing operator:

cmd.Parameters.AddWithValue("@units", units ?? (object)DBNull.Value);
cmd.Parameters.AddWithValue("@range", range ?? (object)DBNull.Value);
cmd.Parameters.AddWithValue("@scale", scale ?? (object)DBNull.Value);
cmd.Parameters.AddWithValue("@description", description ?? (object)DBNull.Value);

Or for more strict type checking:

cmd.Parameters.Add("@units", SqlDbType.Int).Value = units ?? (object)DBNull.Value;
cmd.Parameters.Add("@range", SqlDbType.Int).Value = range ?? (object)DBNull.Value;
cmd.Parameters.Add("@scale", SqlDbType.Int).Value = scale ?? (object)DBNull.Value;
cmd.Parameters.Add("@description", SqlDbType.VarChar).Value = description ?? (object)DBNull.Value;

The operator also be chained:

int?[] a = { null, null, 1 };
Console.WriteLine(a[0] ?? a[1] ?? a[2]);