LOKESH MSBI: Examples of LINQ and LABDMA expression examples, functions and usages for collection types

Write the below code and execute

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="LinqAndLambdaExpressions.aspx.cs"

Inherits="SampleTestingCodes.LinqAndLambdaExpressions" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

</head>

<body>

<div>

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False">

<asp:BoundField DataField="UserId" />

<asp:BoundField DataField="UserName" />

<asp:BoundField DataField="Education" />

</Columns>

</asp:GridView>

</div>

</form>

</body>

</html>

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Data;

namespace SampleTestingCodes

{

public partial class LinqAndLambdaExpressions : System.Web.UI.Page

{

protected void Page_Load(object sender, EventArgs e)

{

DataTable dt = new DataTable();

dt.Columns.Add("UserId", typeof(int));

dt.Columns.Add("UserName", typeof(string));

dt.Columns.Add("Education", typeof(string));

dt.Rows.Add(1, "Lokesh", "B.Tech");

dt.Rows.Add(2, "Vijay", "Msc");

dt.Rows.Add(3, "Balaji", "MS");

dt.Rows.Add(10, "Charan", "B.Tech");

dt.Rows.Add(5, "Durga", "MD");

dt.Rows.Add(6, "Shiva", "B.Tech");

dt.Rows.Add(20, "Venkat", "CA");

//Get the Data from the data table based on the condition

var dsWhere = dt.AsEnumerable().Where(s => s.Field<int>("UserId") >= 1);

var dsWhere1 = (from myRow in dt

.AsEnumerable()

where myRow.Field<int>("UserId") >= 5

select myRow).CopyToDataTable();

var UserId = dt.AsEnumerable().Select(s => s["UserId"]);

//Using Aggregate Method in the LAMBDA Expression

var AdditionOfAllNumbersUsingAggregate = UserId.Aggregate((FirstValue, NextValue) => Convert.ToInt16(FirstValue) + Convert.ToInt16(NextValue));

//Oupput:- 47

//Find the greatest Number in the array

var FindGreatestNumberUsingAggregate = UserId.Aggregate((FirstValue, NextValue) => Convert.ToInt16(NextValue) > Convert.ToInt16(FirstValue) ? NextValue : FirstValue);

//Output:- 20

dt = new DataTable();

dt.Columns.Add("UserId", typeof(int));

dt.Columns.Add("UserName", typeof(string));

dt.Columns.Add("Education", typeof(string));

dt.Rows.Add(1, "Lokesh", "B.Tech");

dt.Rows.Add(1, "Lava", "B.Tech");

bool ConditionAll = dt.AsEnumerable().All(s => s.Field<string>("UserName").Contains("L"));

// Returns True

dt = new DataTable();

dt.Columns.Add("UserId", typeof(int));

dt.Columns.Add("UserName", typeof(string));

dt.Columns.Add("Education", typeof(string));

dt.Rows.Add(1, "Lokesh", "B.Tech");

dt.Rows.Add(1, "Bava", "B.Tech");

//It will works for all having the specific letter

bool All = dt.AsEnumerable().All(s => s.Field<string>("UserName").Contains("L"));

// Returns False all usernames not contains L

//It identifies any of the word contains with this letter returns true

bool Any = dt.AsEnumerable().Any(s => s.Field<string>("UserName").Contains("L"));

//Returns True

//--------------------------------------------------------------------------------------------

DataTable dt1 = new DataTable();

dt1.Columns.Add("UserId", typeof(int));

dt1.Columns.Add("UserName", typeof(string));

dt1.Columns.Add("Education", typeof(string));

dt1.Rows.Add(1, "Lokesh", "B.Tech");

dt1.Rows.Add(2, "Vijay", "Msc");

dt1.Rows.Add(3, "Balaji", "MS");

dt1.Rows.Add(10, "Charan", "B.Tech");

dt1.Rows.Add(5, "Durga", "MD");

dt1.Rows.Add(6, "Shiva", "B.Tech");

dt1.Rows.Add(20, "Venkat", "CA");

var DataViewData = dt1.AsEnumerable().Where(s => s.Field<int>("UserId") >= 4);

GridView1.DataSource = DataViewData.AsDataView();

GridView1.DataBind();

//=====

//Example

//-======

//Gives the average of the column data

var DataAverage = dt1.AsEnumerable().Average(s => s.Field<int>("UserId"));

//OutPut:- 6.7142857142857144

///It will join the esisting list with the sorted list

var DataConcat = dt1.AsEnumerable().Concat(dt1.AsEnumerable().Where(s => s.Field<int>("UserId") >= 10));

//=====

//Example Distinct()

//-======

DataTable dt2 = new DataTable();

dt2.Columns.Add("UserId", typeof(int));

dt2.Columns.Add("UserName", typeof(string));

dt2.Columns.Add("Education", typeof(string));

dt2.Rows.Add(1, "Lokesh", "B.Tech");

dt2.Rows.Add(2, "Vijay", "Msc");

dt2.Rows.Add(3, "Lokesh", "MS");

dt2.Rows.Add(10, "Charan", "B.Tech");

var DataDistinct = dt2.AsEnumerable().Select(s => s.Field<string>("UserName")).Distinct();

//output:-

//[0] = "Lokesh"

//[1] = "Vijay"

//[2] = "Charan"

var DataElementAt = dt2.AsEnumerable().ElementAt(0).Field<string>("UserName");

//output:-

//DataElementAt "Lokesh"

var DataElementAtOrDefault = dt2.AsEnumerable().ElementAtOrDefault(0).Field<string>("UserName");

var DataFirst = dt2.AsEnumerable().First(s => s.Field<int>("UserId") > 2);

var DataLast = dt2.AsEnumerable().Last(s => s.Field<int>("UserId") > 2);

var DataGroupBy = dt2.AsEnumerable().Select(s => new { UserName = s.Field<string>("UserName"), Education = s.Field<string>("Education") }).GroupBy(s => s.UserName).Select(s => new { Name = s.Key, Count = s.Select(t => t.Education).Count(), Educations = s.Select(t => t.Education).ToArray() });

var DataLongCount = dt2.AsEnumerable().LongCount();//It returns Int64 bit count

var DataCount = dt2.AsEnumerable().Count();//It returns only int count

//=====

//Example OfType()

//-======

DataTable dt3 = new DataTable();

dt3.Columns.Add("UserId", typeof(int));

dt3.Columns.Add("UserName", typeof(string));

dt3.Columns.Add("Education", typeof(string));

dt3.Columns.Add("Comments", typeof(object));

dt3.Rows.Add(1, "Lokesh", "B.Tech",234);

dt3.Rows.Add(15, "Vijay", "Msc","good");

dt3.Rows.Add(3, "Lokesh", "MS","Raghu master");

dt3.Rows.Add(10, "Charan", "B.Tech",100);

var DataOfType = dt3.AsEnumerable().Select(s => s.Field<object>("Comments")).OfType<int>();

var DataOfTypeString = dt3.AsEnumerable().Select(s => s.Field<object>("Comments")).OfType<string>();

var DataOrderBy = dt3.AsEnumerable().OrderBy(s => s.Field<string>("UserName")).CopyToDataTable();

DataTable dtt = new DataTable();

dtt = DataOrderBy;

var DataOrderByDescending = dt3.AsEnumerable().OrderByDescending(s => s.Field<string>("UserName")).CopyToDataTable();

var DataReverse = dt3.AsEnumerable().Select(s => s.Field<string>("UserName")).Reverse();

var DataReverse1 = dt3.AsEnumerable().Select(s => s.Field<int>("UserId")).Reverse();

//Skip will works as

//skip the collection from starting to count number of records

var DataSkip = dt3.AsEnumerable().Select(s => s.Field<int>("UserId")).Skip(1);

var DataToDictionary = dt3.AsEnumerable().ToDictionary(s => s.Field<int>("UserId"));

}

Happy Coding JJJJJJJJJJJJJJJJJJJJJJJJJ

LOKESH MSBI

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Wednesday, June 18, 2014

Examples of LINQ and LABDMA expression examples, functions and usages for collection types

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