Introduction
Projection operators
transform an object into another object with different properties. By using the
projection operators, we can construct a new object that has the properties of
the objects from which it has been constructed.
Projection Operators used in LINQ are:
Select works with one collection whereas
SelectMany works with more than one collection. Projection transforms the
query result into the form defined by the us.
The
Select operator has the opportunity to
project a new type of element, however, and its often useful to think of the
Select operator as performing a
transformation or mapping.
SelectMany
operator will flatten the sub-sequences
into a single output sequence we can say
SelectMany as something like a nested iterator or nested
foreach loop that digs objects out of a
sequence inside a sequence.
The below example code demonstrates how to use
projections in LINQ to SQL query.
Example
First open the Visual Studio
Then follow the step- File>New>Project then
follow the path- Visual C#>Windows>Console Application>OK as shown below:
Then write the following code:
using
System;
using
System.Collections.Generic;
using
System.Linq;
using
System.Text;
public class MainClass
{
public static void Main()
{
int[] numbers = { 7, 4, 61, 2, 22 };
var numsPlusOne =
from n in
numbers
select n + 1;
Console.WriteLine("Numbers
+ 1:");
foreach (var i
in numsPlusOne)
{
Console.WriteLine(i);
}
Console.ReadLine();
}
}
Output
Resources
How Calculation is performed by SELECT statement in T-SQL
Using Select Statement in SQLite
SELECT Statement in Oracle SQL Plus
How to perform the Rename Operation with Select Statement in SQL
How Where clause is used with Calculation in T-SQL