public static void Demo1()
{
var queryMethod = from emp in OuterJoinDataSource.Employee.GetAllEmployees()
join address in OuterJoinDataSource.Address.GetAddress()
on emp.AddressId equals address.ID into EmployeeAddressGroup
from address in EmployeeAddressGroup.DefaultIfEmpty()
select new
{
emp,
address
};
foreach (var item in queryMethod)
{
Console.WriteLine($"Name : {item.emp.Name}, Address : {item.address?.AddressLine} ");
}
}
static void Main(string[] args)
{
WriteLine(" INNER JOIN");
var innerJoin = Employee.GetEmployees() // outer data Source
.Join(Address.GetAlladdress(), // Inner data Source
employee => employee.addressId, // outer
address => address.addressId,
(employee, address) => new
{
EmployeeName = employee.empName,
AddressLine = address.addressLine
}
).ToList();
foreach (var i in innerJoin)
{
WriteLine($"Employee Name {i.EmployeeName} => Address :{i.AddressLine}");
}
WriteLine("*********LEFT JOIN Method Syntax**********");
var leftJoin = Employee.GetEmployees().
GroupJoin(Address.GetAlladdress(),
employee => employee.addressId,
address => address.addressId,
(employee, address) => new { employee, address }).
SelectMany(x => x.address.DefaultIfEmpty(),
(employee, address) => new
{
EmployeeName = employee.employee.empName,
Address = address == null ? "Address not Mentioned" : address.addressLine
});
foreach (var i in leftJoin)
{
WriteLine($"Employee Name {i.EmployeeName} => Address :{i.Address}");
}
WriteLine("*********LEFT JOIN Query Syntax**********");
var leftJoin1 = from employee in Employee.GetEmployees()
join address in Address.GetAlladdress() on
employee.addressId equals address.addressId into
EmployeeAddressGroup
from address1 in
EmployeeAddressGroup.DefaultIfEmpty()
select new
{
EmployeeName = employee.empName,
Address = address1 == null ? "Address not Mentioned"
: address1.addressLine
};
foreach (var i in leftJoin1)
{
WriteLine($"Employee Name {i.EmployeeName} => Address :{i.Address}");
}
WriteLine("************CROSS JOIN with SELECT MANY **********");
var crossJoin = Employee.GetEmployees().
SelectMany(address => Address.GetAlladdress(), (employee, address) => new
{
EmployeeName = employee.empName,
Address = address.addressLine
}
);
WriteLine("***********CROSS JOIN with Join method**********");
var crossJoin1 = Employee.GetEmployees().Join(Address.GetAlladdress(),
employee => false,
address => false, (employee, address) => new
{
EmployeeName = employee.empName,
Address = address.addressLine
}
);
foreach (var i in crossJoin1)
{
WriteLine($" Employee Name : {i.EmployeeName} , Address :{i.Address}");
}
WriteLine(" CROSS JOIN QUERY SYNTAX******");
var crossJoin2 = from employee in Employee.GetEmployees()
from address in Address.GetAlladdress()
select new
{
EmployeeName = employee.empName,
Address = address.addressLine
};
foreach (var i in crossJoin2)
{
WriteLine($" Employee Name : {i.EmployeeName} , Address :{i.Address}");
}
}