Joining Multiple Inputs into One Output Sequence

Rajesh081725
Posted by Rajesh081725 under LINQ category on | Points: 40 | Views : 855
You can use a LINQ query to create an output sequence that contains elements from more than one input sequence. The following example shows how to combine two in-memory data structures, but the same principles can be applied to combine data from XML or SQL or DataSet sources. Assume the following two class types:

C#
class Student
{
public string First { get; set; }
public string Last {get; set;}
public int ID { get; set; }
public string Street { get; set; }
public string City { get; set; }
public List<int> Scores;
}

class Teacher
{
public string First { get; set; }
public string Last { get; set; }
public int ID { get; set; }
public string City { get; set; }
}



The following example shows the query:

C#
class DataTransformations
{
static void Main()
{
// Create the first data source.
List<Student> students = new List<Student>()
{
new Student {First="Svetlana",
Last="Omelchenko",
ID=111,
Street="123 Main Street",
City="Seattle",
Scores= new List<int> {97, 92, 81, 60}},
new Student {First="Claire",
Last="O'Donnell",
ID=112,
Street="124 Main Street",
City="Redmond",
Scores= new List<int> {75, 84, 91, 39}},
new Student {First="Sven",
Last="Mortensen",
ID=113,
Street="125 Main Street",
City="Lake City",
Scores= new List<int> {88, 94, 65, 91}},
};

// Create the second data source.
List<Teacher> teachers = new List<Teacher>()
{
new Teacher {First="Ann", Last="Beebe", ID=945, City = "Seattle"},
new Teacher {First="Alex", Last="Robinson", ID=956, City = "Redmond"},
new Teacher {First="Michiyo", Last="Sato", ID=972, City = "Tacoma"}
};

// Create the query.
var peopleInSeattle = (from student in students
where student.City == "Seattle"
select student.Last)
.Concat(from teacher in teachers
where teacher.City == "Seattle"
select teacher.Last);

Console.WriteLine("The following students and teachers live in Seattle:");
// Execute the query.
foreach (var person in peopleInSeattle)
{
Console.WriteLine(person);
}

Console.WriteLine("Press any key to exit.");
Console.ReadKey();
}
}
Output:
The following students and teachers live in Seattle:
Omelchenko
Beebe

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