vs2013 linq to mysql

using (WorkerContainer db = new WorkerContainer()){
IQueryable<workers_info> linq = from c in db.workers_info select c;
List<workers_info> list = linq.ToList();
}

using (WorkerContainer db = new WorkerContainer()){
var info = db.workers_info.SingleOrDefault<workers_info>(s => s.id == 2);
info.email = "xxxxxx@126.com";
　　　　　　　　　　 db.SaveChanges();
}

using (WorkerContainer db = new WorkerContainer()){
workers_info infoModel = new workers_info();
infoModel.email = "22222222";

infoModel.salary = 3;
infoModel.workername = "zhaoiyue";
infoModel.EmployedDates = DateTime.Now;
infoModel.department = "12312";

db.workers_info.Add(infoModel);
db.SaveChanges();
}