The following is a very brief demonstration of Linq to SQL to retrieve, insert, update, and delete a row of data. I make no claims that this is the most efficient or best practice of Linq, but simply a starting point.
There are various resources all over the internet for extended information on Linq; these would be better suited to discuss why to use Linq as well as advanced how-to information as well.
For demonstration purposes, we’ll use a fictious table schema based around a User.
Retrieve Record
public static User GetUser(int UserID)
{
MasterDataContext dc = new MasterDataContext();
var query = from a in dc.Users
where a.UserID == UserID
select a;
return query.Single<User>();
}
Create Record
public static void CreateUser(string EmailAddress, string Password, string Alias, string FirstName, string LastName, string City, string State, string Country, string Zip, string Description)
{
MasterDataContext dc = new MasterDataContext();
var usr = new User();
usr.Email = EmailAddress;
usr.Password = Password;
usr.Alias = Alias;
usr.FirstName = FirstName;
usr.LastName = LastName;
usr.City = City;
usr.State = State;
usr.Country = Country;
usr.Zip = Zip;
usr.Description = Description;
usr.Created = DateTime.Now;
usr.LastUpdated = DateTime.Now;
dc.Users.InsertOnSubmit(usr);
dc.SubmitChanges();
}
Update Record
public static void UpdateUser(int UserID, string EmailAddress, string Password, string Alias, string FirstName, string LastName, string City, string State, string Country, string Zip, string Description)
{
MasterDataContext dc = new MasterDataContext();
var query = from a in dc.Users
where a.UserID == UserID
select a;
var usr = query.Single();
usr.Email = EmailAddress;
usr.Password = Password;
usr.Alias = Alias;
usr.FirstName = FirstName;
usr.LastName = LastName;
usr.City = City;
usr.State = State;
usr.Country = Country;
usr.Zip = Zip;
usr.Description = Description;
usr.LastUpdated = DateTime.Now;
dc.SubmitChanges();
}
Delete Record
public static void DeleteUser(int UserID)
{
MasterDataContext dc = new MasterDataContext();
var query = from a in dc.Users
where a.UserID == UserID
select a;
var usr = query.Single<User>();
dc.Users.DeleteOnSubmit(usr);
dc.SubmitChanges();
}
