private static void DisplayEmployees(DemoDBContext db)
{
//write a query to display all employees
var query = from e in db.Employees
orderby e.EmployeeID
select e;
Console.WriteLine("All employees in the database: ");
foreach (var item in query)
{
Console.WriteLine(item.EmployeeID + " " + item.Name);
}
}
static void Main(string[] args)
{
//using is the same thing as "try finally"
//keeps from leaving the connection open all the time
using(var db = new DemoDBContext())
{
Console.Write("Employee Name: ");
var name = Console.ReadLine();
var employee = new Employee { Name = name };
db.Employees.Add(employee);
//instead of setting up a connection string
//and all the other things to put data into the database use this:
db.SaveChanges();
//call method to display employees in database
DisplayEmployees(db);
//Ask user for emp to modify
Console.Write("Enter ID of employee to modify name: ");
int empID = int.Parse(Console.ReadLine());
Console.Write("Enter new name: ");
string newName = Console.ReadLine();
//update employee
//you need a First or To List in order to get objects
Employee empToChange = (from e in db.Employees
where e.EmployeeID == empID
select e).First();
empToChange.Name = newName;
db.SaveChanges();
//call method to display employees in database
DisplayEmployees(db);
//delete
Console.Write("ID of employee to delete: ");
int delID = int.Parse(Console.ReadLine());
//delete employee
Employee empToRemove = (from e in db.Employees
where e.EmployeeID == delID
select e).First();
db.Employees.Remove(empToRemove);
db.SaveChanges();
//call method to display employees in database
DisplayEmployees(db);
}
}