Before all of you move forward read this posting, please ensure that you understand what is generic method in C#.
Ok, let’s move on. When dealing with database, we’re almost certainly dealing with CRUD < Create, Read, Update, Delete >. Therefor, if we can make a generic method code to handle CRUD for any table, we’ll get lot’s of advantage.
The first Generic method we want to explain first is Create < or Insert in database term >,
public static void Insert<TClass> (TClass item) where TClass :class
{
using (var dc = new ApotekDataContext())
{
var table = dc.GetTable();
table.InsertOnSubmit(item);
dc.SubmitChanges();
}
}
The second generic method is Read < or Select in database term >, we separate method for select into 2 method,
SELECTALL and SELECTBYID. Let’s view our SELECTALL method
public static List<TClass> SelectAll() where TClass:class
{
using(var dc=new ApotekDataContext())
{
var table = dc.GetTable().ToList();
return table;
}
}
so simple isn’t it. Before we move to the SELECTBYID, let’s imagine what is the complexity of SELECTBYID method.
The trap of this method is “how to get the ID/primaryID”. If we pass this trap, everything will be fine.
public static TClass SelectById<TClass,TId>(TId primaryKey) where TClass : class
{
using (var dc = new ApotekDataContext())
{
var table = dc.GetTable();
var modelMap = table.Context.Mapping;
var dataMembers = modelMap.GetMetaType(typeof(TClass)).DataMembers;
//Get the primary key field name
var pk = (dataMembers.Single(m => m.IsPrimaryKey)).Name;
var t = (from selected in table
where
selected.GetType().GetProperty(pk).GetValue(selected, null).ToString()==primaryKey.ToString()
select selected).SingleOrDefault();
return t;
}
}
Weks.. time to work.. we have to go, we’ll add the method for update and delete later. Thanks
.
), piss ya mas budi, pak irwan dan pak bambang 
