static void Main1()
{
//Sql Like Syntax :
var result1 = from e in Employee5.GetAllEmployees()
join d in Department1.GetAllDepartments()
on e.DepartmentId equals d.Id into eGroup
from dept in eGroup.DefaultIfEmpty()
select new
{
EmployeeName = e.Name,
DepartmentName = dept == null ? "No Department" : dept.Name,
};
//Extension Method Syntax: Here we Use GroupJoin to Perform the Left Join
var result2 = Employee5.GetAllEmployees()
.GroupJoin(Department1.GetAllDepartments(),
emp => emp.DepartmentId,
dept => dept.Id,
(emp, depts) => new
{
emp,
depts
})
.SelectMany(z => z.depts.DefaultIfEmpty(),
(a, department) => new
{
EmployeeName = a.emp.Name,
DepartmentName = department == null ? "Not Having Department" : department.Name
});
foreach (var employee in result1)
{
Console.WriteLine(employee.EmployeeName + "\t\t\t" + employee.DepartmentName);
}
}
static void Main1()
{
//Here we wanna to get All the Information about an employee
//Linq Syntax:
var employees1 = Employee5.GetAllEmployees()
.Join(Department1.GetAllDepartments(),
emp => emp.DepartmentId,
dept => dept.Id,
(employee, department) => new //Here we get a Combnation of the Employee and Department as result of Join
{
EmployeeName = employee.Name,
DepartmentName = department.Name //In the End we get IEnumerable<AnonymousType(Employee)>
});
//Sql Like Syntax:
var employees2 = from emp in Employee5.GetAllEmployees()
join dept in Department1.GetAllDepartments()
on emp.DepartmentId equals dept.Id
select new
{
EmployeeName = emp.Name,
DepartmentName = dept.Name
};
//Now We have to Loop throug all the Anonymous Type in the result Collection
foreach (var employee in employees2)
{
Console.WriteLine(employee.EmployeeName + "\t\t" + employee.DepartmentName);
}
}
static void Main()
{
//Sql Like Syntax:
var result1 = from e in Employee5.GetAllEmployees()
from d in Department1.GetAllDepartments()
select new
{
e,
d
};
//By Using SelectMany Opeartor or Extension Method
var result2 = Employee5.GetAllEmployees().SelectMany(e => Department1.GetAllDepartments(), //This will associate each employee with all the Departments
(e, d) => new { e, d }); //Now we have a List<Emp,Dep> in a Cross Join Format
//By using Join Extension Method:
var result3 = Employee5.GetAllEmployees().Join(Department1.GetAllDepartments(),
e => true,
d => true,
(e, d) => new { e, d });
Console.WriteLine("Total Count = " + result3.Count());
foreach (var combo in result3)
{
Console.WriteLine(combo.e.Name + "\t\t\t" + combo.d.Name);
}
Console.WriteLine("/////////////////////////////////////");
}
static void Main1()
{
//Linq Syntax For GroupJoin:
var employeesByDepartment1 = Department1.GetAllDepartments()
.GroupJoin(Employee5.GetAllEmployees(),
d => d.Id,
e => e.DepartmentId,
(department, employees) => new
{
Department = department,
Employees = employees.OrderBy(e => e.Name)
});
//Sql Like Syntax For GroupJoin:
var employeesByDepartment2 = from d in Department1.GetAllDepartments()
join e in Employee5.GetAllEmployees()
on d.Id equals e.DepartmentId into eGroup //Please note: Group Join uses the join operator and the into keyword to group the results of the join.
select new
{
Department = d,
Employees = eGroup.OrderBy(e => e.Name)
};
//It Something Like a List<Group> or List<Department having Employeess>
foreach (var department in employeesByDepartment2)
{
Console.WriteLine(department.Department.Name);
foreach (var employee in department.Employees)
{
Console.WriteLine(" " + employee.Name);
}
Console.WriteLine();
}
}