-
Working with LINQ To SQL
-
During these days I am developing a little project with LINQ To SQL for understand this new tecnology. It is a little web application for configure newsletters. Here I report some examples with LINQ To SQL:
Example using JOIN and Anonimous types:
var objs=from s in dal.Subscribers
join ns in dal.SubScribersNewsLetters on s.nlsub_email equals ns.sunl_submail
where ns.sunl_nlid==idNL
select new{
s.nlsub_email,
s.nlsub_RagioneSociale,
s.nlsub_citta
};
Example for insert multiple objects in one step:
List<SubScribersNewsLetter> inserted=new List<SubScribersNewsLetter>();
foreach(GridViewRow gr in this.gvUtenti.Rows){
CheckBox cb = (CheckBox)gr.FindControl("cbAssocia");
if(cb.Checked){
string mail=gr.Cells[2].Text;
if (this.NotPresent(objs,mail))
{
SubScribersNewsLetter tmp=new SubScribersNewsLetter();
tmp.sunl_nlid=idNL;
tmp.sunl_submail=mail;
inserted.Add(tmp);
}
}
}
dal.SubScribersNewsLetters.InsertAllOnSubmit<SubScribersNewsLetter>(inserted);
dal.SubmitChanges();
Example for get a single record object:
var objs = from o in dal.Subscribers
where o.nlsub_email == mail
select o;
if (objs.Count<Subscriber>() > 0)
return objs.Single<Subscriber>();
Example for IQueryable:
IQueryable<Subscriber> objs = from o in dal.Subscribers
join n in dal.SubScribersNewsLetters on o.nlsub_email equals n.sunl_submail
where n.sunl_nlid == nl
select o;
Bye
Antonio