LINQ Query For Insert Update Delete Operation

Hope you are using EF..

1. For insert you no need to go for LINQ,
just take instance object of table from Context and add table object.

2.Update operation..

protected void btnUpdate_Click(object sender, EventArgs e)
{
    int ContactID = Convert.ToInt32(Request.QueryString["ContactID"]); //This is contact reference ID, i am taking it from QS..
    ContactContext ctxContact = new ContactContext();
    tblContact Contact = ctxContact.tblContacts.SingleOrDefault(ID => ID.ID == ContactID); //Here ID is primary key of the table, This is for update reference.
    Contact.Name = txtName.Text;
    Contact.Address = txtAddress.Text;
    Contact.PhoneNo = Convert.ToInt64(txtPhone.Text);
    if (objDB.SaveChanges() == 1)    //Save method will return 1 if success..
    {
        //Success alert..
    }
}

3.Delete operation..

protected void btnDelete_RowCommand(object sender, EventArgs e)
{
    int ContactID = Convert.ToInt32(Request.QueryString["ContactID"]); //This is contact reference ID, i am taking it from QS..
    dbTestEntities objDB = new dbTestEntities();
    tblContact obj=objDB.tblContacts.SingleOrDefault(ID=>ID.ID==intContactID);
    objDB.tblContacts.DeleteObject(obj);
    if(objDB.SaveChanges()==1)    //Save method will return 1 if success..
    {
        //Success alert..
    }
}