private void Button_Click_19(object sender, RoutedEventArgs e)
{
DataGrid.ItemsSource = Emps.Where(emp => emp.Job.Equals(Emps.Where(a => a.Ename.Equals("BLAKE")).Select(a => a.Job).First()));
Console.WriteLine(Emps.Where(a => a.Ename.Equals("BLAKE")).Select(a => a.Job).First());
}
//Z pomocą języka LINQ i metody SelectMany wykonaj złączenie
//typu CROSS JOIN
public void Przyklad12()
{
// Lambda and Extension methods
var res = Emps.SelectMany(e => Depts, (emp, dept) => new { emp, dept });
}
//Znajdź pracownika z najwyższą pensją wykorzystując metodę Aggregate()
public void Przyklad11()
{
var res = Emps.Aggregate((a, b) => a.Salary > b.Salary ? a : b);
Console.WriteLine(res);
}
/// <summary>
/// Zwróć wartość "true" jeśli choć jeden
/// z elementów kolekcji pracuje jako "Backend programmer".
/// </summary>
public void Przyklad8()
{
// Lambda and Extension methods
var res = Emps.Any(emp => emp.Job == "Backend programmer");
}
/// <summary>
/// SELECT Ename, Job, Hiredate FROM Emps
/// UNION
/// SELECT "Brak wartości", null, null;
/// </summary>
public void Przyklad10Button_Click()
{
// Lambda and Extension methods
var res = (Emps.Select(emp => new { emp.Ename, emp.Job, emp.HireDate })).Union(Emps.Select(emp => new { emp.Ename, emp.Job, emp.HireDate }).Where(emp => emp.Ename == "Brak wartości" && emp.Job == null && emp.HireDate == null));
}
/// <summary>
/// Zwróć wartość "true" jeśli choć jeden
/// z elementów kolekcji pracuje jako "Backend programmer".
/// </summary>
public void Przyklad8()
{
var p8 = Emps.Any(x => x.Job.Equals("Backend programmer"));
Console.WriteLine("\n" + p8);
}
/// <summary>
/// SELECT Emps.Ename, Emps.Job, Depts.Dname FROM Emps
/// INNER JOIN Depts ON Emps.Deptno=Depts.Deptno
/// Rezultat: Złączenie kolekcji Emps i Depts.
/// </summary>
public void Przyklad6()
{
// Lambda and Extension methods
var res = Emps.Join(Depts, emp => emp.Deptno, dept => dept.Deptno, (emp, dept) => new { emp, dept });
}
/// <summary>
/// SELECT TOP 1 * FROM Emp WHERE Job="Frontend programmer"
/// ORDER BY HireDate DESC;
/// </summary>
public void Przyklad9()
{
var res = Emps.Where(emp => emp.Job == "Frontend programmer")
.OrderByDescending(emp => emp.HireDate).FirstOrDefault();
}
//Znajdź pracownika z najwyższą pensją wykorzystując metodę Aggregate()
public void Przyklad11()
{
var res = Emps.Aggregate((e1, e2) => e1.Salary > e2.Salary ? e1 : e2);
}
/// <summary>
/// SELECT * FROM Emps WHERE Salary=(SELECT MAX(Salary) FROM Emps);
/// </summary>
public void Przyklad4()
{
var res = Emps.Where(emp => emp.Salary == Emps.Max(e => e.Salary));
}
/// <summary>
/// Zwróć wartość "true" jeśli choć jeden
/// z elementów kolekcji pracuje jako "Backend programmer".
/// </summary>
public void Przyklad8()
{
var res = Emps.Any(emp => emp.Job == "Backend programmer");
}
/// <summary>
/// SELECT MAX(Salary) FROM Emps;
/// </summary>
public void Przyklad3()
{
var res = Emps.Max(emp => emp.Salary);
}
/// <summary>
/// SELECT * FROM Emps Job = "Frontend programmer" AND Salary>1000 ORDER BY Ename DESC;
/// </summary>
public void Przyklad2()
{
var res = Emps.Where(emp => emp.Job == "Frontend programmer" && emp.Salary > 1000)
.OrderByDescending(emp => emp.Ename);
}
private void Button_Click_21(object sender, RoutedEventArgs e)
{
DataGrid.ItemsSource = Emps.Where(emp => emp.Sal == Emps.Where(a => a.Deptno == emp.Deptno).Select(a => a.Sal).First());
}
/// <summary>
/// SELECT TOP 1 * FROM Emp WHERE Job="Frontend programmer"
/// ORDER BY HireDate DESC;
/// </summary>
public void Task9()
{
var res = Emps.Where(e => e.Job == "Frontend programmer").OrderByDescending(e => e.HireDate).FirstOrDefault();
}
//Find the employee with the highest salary using the Aggregate () method
public void Task11()
{
var res = Emps.Aggregate(Emps.First(),
(bestPaid, next) =>
next.Salary > bestPaid.Salary ? next : bestPaid);
}
//Find the employee with the highest salary using the Aggregate () method
public void Task11()
{
var res = Emps.Aggregate((emp, dept) => emp.Salary > dept.Salary ? emp : dept);
}
/// <summary>
/// SELECT * FROM Emps Job = "Frontend programmer" AND Salary>1000 ORDER BY Ename DESC;
/// </summary>
public void Task2()
{
var res = Emps.Where(e => e.Job == "Frontend programmer" && e.Salary > 1000).OrderByDescending(e => e.Ename);
}
//Znajdź pracownika z najwyższą pensją wykorzystując metodę Aggregate()
public void Przyklad11()
{
var p11 = Emps.Aggregate((x, y) => y.Salary > x.Salary ? y : x);
Console.WriteLine("\n" + p11);
}
/// <summary>
/// SELECT * FROM Emps WHERE Salary=(SELECT MAX(Salary) FROM Emps);
/// </summary>
public void Task4()
{
var res = Emps.Where(e => e.Salary == Emps.Max(e => e.Salary));
}
/// <summary>
/// SELECT Job AS Praca, COUNT(1) LiczbaPracownikow FROM Emps GROUP BY Job;
/// </summary>
public void Przyklad7()
{
// Lambda and Extension methods
var res = Emps.Select(emp => new { Praca = emp.Job, LiczbaPracownikow = Emps.Count(emp2 => emp2.Job == emp.Job) }).GroupBy(emp => emp.Praca);
}
/// <summary>
/// SELECT ename AS FirstName, job AS EmployeeJob FROM Emps;
/// </summary>
public void Task5()
{
var res = Emps.Select(e => new { Name = e.Ename, EmployeeJob = e.Job });
}
/// <summary>
/// SELECT TOP 1 * FROM Emp WHERE Job="Frontend programmer"
/// ORDER BY HireDate DESC;
/// </summary>
public void Przyklad9()
{
// Lambda and Extension methods
var res = Emps.Where(emp => emp.Job == "Frontend programmer").OrderByDescending(emp => emp.HireDate).First();
}
/// <summary>
/// SELECT Emps.Ename, Emps.Job, Depts.Dname FROM Emps
/// INNER JOIN Depts ON Emps.Deptno=Depts.Deptno
/// Result: Joining collections Emps and Depts.
/// </summary>
public void Task6()
{
var res = Emps.Join(Depts, e => e.Deptno, d => d.Deptno, (r, l) => new { r, l }).Select(l => new { l.r.Ename, l.r.Job, l.l.Deptno });
}
//Znajdź pracownika z najwyższą pensją wykorzystując metodę Aggregate()
public void Przyklad11()
{
// Lambda and Extension methods
var res = Emps.Aggregate((current, next) => current.Salary > next.Salary ? current : next);
}
/// <summary>
/// SELECT Job AS EmployeeJob, COUNT(1) EmployeeNuber FROM Emps GROUP BY Job
/// </summary>
public void Task7()
{
var res = Emps.GroupBy(e => e.Job)
.Select(e => new { EmployeeJob = e.Key, EmployeeNumber = Emps.Distinct().Count() });
}
/// <summary>
/// Zwróć wartość "true" jeśli choć jeden
/// z elementów kolekcji pracuje jako "Backend programmer".
/// </summary>
public void Przyklad8()
{
var res = Emps.Where(x => x.Job == "Backend programmer");
Console.WriteLine(res.Any());
}
/// <summary>
/// Return value "true" if at least one of
/// the elements of collection works as "Backend programmer".
/// </summary>
public void Task8()
{
var res = Emps.Any(e => e.Job == "Backend programmer");
}
/// <summary>
/// SELECT MAX(Salary) FROM Emps;
/// </summary>
public void Task3()
{
var max = Emps.Max(e => e.Salary);
}
private void Button_Click_18(object sender, RoutedEventArgs e)
{
DataGrid.ItemsSource = Emps.Where(emp => emp.Sal == Emps.Min(a => a.Sal));
}
