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)); }