Like statements parameterized @query%

I would like to ask your help about parameterizing a like statement.I need to get the rows which starts with the variable code. I have a problem with my sql statement in c#.whenever i try to use this:

SqlCommand sql2= sql.SelectCommand = new SqlCommand(@"Select * 
             from book 
             where Date like @date+'%' 
             order by Category,Paticulars,Description,Amount", 
             this.connection);
sql.SelectCommand.Parameters.AddWithValue("@date", code);
SqlDataReader reader=sql2.ExecuteReader();

it does not return anything.but if i tried to add a '%' before the date it works properly.