public static Employee FindByKey(object key)
{
var context = new SoftUniEntities();
var employee = context.Employees
.Find(key);
return employee;
}
public static void Add(Employee employee)
{
var context = new SoftUniEntities();
context.Employees.Add(employee);
context.SaveChanges();
Console.WriteLine("Employee has been added.");
}
public static void Modify(int employeeId, string property, object value)
{
var context = new SoftUniEntities();
var selectedEmployee = context.Employees.Find(employeeId);
selectedEmployee.GetType().GetProperty(property).SetValue(selectedEmployee, value);
context.SaveChanges();
Console.WriteLine("Employee has been modified.");
}
public static void Delete(int employeeId)
{
var context = new SoftUniEntities();
var selectedEmployee = context.Employees.Find(employeeId);
context.Employees.Remove(selectedEmployee);
context.SaveChanges();
Console.WriteLine("Employee has been deleted.");
}
//LINQ query:
public static void PintNamesWithLinqQuery()
{
var context = new SoftUniEntities();
var employees = context.Employees
.Where(e => e.Projects.Any(p => p.StartDate.Year == 2002))
.Select(e => e.FirstName);
//foreach (var employee in employees)
//{
// Console.WriteLine(employee);
//}
}
static void Main()
{
var context = new SoftUniEntities();
//call the stored procedure (see it in SoftUniEntities.Context.cs)
//to find all projects for given employee by his/her firstname and lastname
var projects = context.GetProjectsByEmployee("Ruth", "Ellerbrock");
foreach (var project in projects)
{
Console.WriteLine("{0} - {1} - {2}", project.Name, project.Description, project.StartDate);
}
}
//Find all employees who have projects with start date in the year 2002. Select only their first name.
//native SQL query:
public static void PintNamesWithNativeQuery()
{
var context = new SoftUniEntities();
string query = @"SELECT e.[FirstName]
FROM [SoftUni].[dbo].[Employees] e
JOIN EmployeesProjects ep ON ep.EmployeeID = e.EmployeeID
JOIN Projects p ON ep.ProjectID = p.ProjectID
WHERE DATEPART(yy, p.StartDate) = 2002";
var employees = context.Database.SqlQuery<string>(String.Format(query)).ToList();
//foreach (var employee in employees)
//{
// Console.WriteLine(employee);
//}
}
static void Main()
{
var contextOne = new SoftUniEntities();
var empOne = contextOne.Employees.Find(1);
empOne.FirstName = "Mincho";
var contextTwo = new SoftUniEntities();
var empTwo = contextTwo.Employees.Find(1);
empTwo.FirstName = "Zdravko";
contextOne.SaveChanges();
contextTwo.SaveChanges();
//result with [Concurrency Mode] = None: second win: the first name is set to Zdravko
//result with [Concurrency Mode] = Fixed: first win: the first name is set to Mincho
}
static void Main()
{
//Measure the difference in performance in both cases with a Stopwatch.
var context = new SoftUniEntities();
//Establish connection to server in advance
var totalCount = context.Employees.Count();
var sw = new Stopwatch();
sw.Start();
PintNamesWithNativeQuery();
Console.WriteLine("Native: {0}", sw.Elapsed);
sw.Restart();
PintNamesWithLinqQuery();
Console.WriteLine("Linq: {0}", sw.Elapsed);
//result: Native: 00:00:00.0503817; Linq: 00:00:00.0081855
}
