asp dot net,c#.net,maps,code sample: C# - Remove Columns that contains null values in Data Table

Source Code:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="RemoveColumnInDataTable._Default" %>

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

<title>Removing Columns in DataTable</title>

</head>

<body>

<div>

<asp:Label ID="lbl" Text="Before" runat="server" Style="font-size: small">

</asp:Label>

<br />

<asp:GridView ID="GridView1" runat="server" Width="30%" BackColor="White" BorderColor="#CCCCCC"

BorderStyle="None" BorderWidth="1px" CellPadding="3">

</asp:GridView>

<br />

<asp:Button ID="OnBtnClick" runat="server" Text="Remove Null/Empty Value Column"

OnClick="OnBtnClick_Click" />

<br />

<asp:Label ID="Label1" Text="After" runat="server" Style="font-size: small">

</asp:Label>

<asp:GridView ID="GridView2" runat="server" Width="30%" BackColor="White" BorderColor="#CCCCCC"

BorderStyle="None" BorderWidth="1px" CellPadding="3">

</asp:GridView>

</div>

</form>

</body>

</html>

Cs Code:

using System;

using System.Collections;

using System.Configuration;

using System.Data;

using System.Linq;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.HtmlControls;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Xml.Linq;

namespace RemoveColumnInDataTable

{

/// <summary>

/// Author etechpulse

/// To remove a particular column in a DataTable if all values in the row of that column are null or empty.

/// </summary>

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

{

DataTable dtTemp = new DataTable();

protected void Page_Load(object sender, EventArgs e)

{

//print the Columns in the DataTable to see if what column(s) are deleted

dtTemp = StaticTable();

GridView1.DataSource = dtTemp;

GridView1.DataBind();

}

private DataTable StaticTable()

{

DataTable _dt = new DataTable();

DataRow _dr = null;

//Create the Columns Definition

_dt.Columns.Add(new DataColumn("Column1", typeof(string)));

_dt.Columns.Add(new DataColumn("Column2", typeof(string)));

_dt.Columns.Add(new DataColumn("Column3", typeof(string)));

//Add the first Row to each columns defined

_dr = _dt.NewRow();

//Add dummy values to each rows

_dr["Column1"] = "A";

_dr["Column2"] = string.Empty; // but it will be converted to empty

_dr["Column3"] = "C";

_dt.Rows.Add(_dr);

//Add the second Row to each columns defined

_dr = _dt.NewRow();

_dr["Column1"] = null;

_dr["Column2"] = null;// but it will be converted to empty

_dr["Column3"] = "F";

_dt.Rows.Add(_dr);

//You can continue adding rows here

return _dt;

}

private DataTable CheckDataTableColumn()

{

// DataTable dt = StaticTable();

bool flag = false;

int counter = 0;

EXIT:

for (int i = counter; i < dtTemp.Columns.Count; i++)

{

for (int x = 0; x < dtTemp.Rows.Count; x++)

{

if (string.IsNullOrEmpty(dtTemp.Rows[x][i].ToString()))

{

flag = true; //means there is an empty value

}

else

{

//means if it found non null or empty in rows of a particular column

flag = false;

counter = i + 1;

goto EXIT;

}

if (flag == true)

{

dtTemp.Columns.Remove(dtTemp.Columns[i]);

i--;

}

return dtTemp;

}

protected void OnBtnClick_Click(object sender, EventArgs e)

{

dtTemp = CheckDataTableColumn();

if (dtTemp.Rows.Count > 0)

{

foreach (DataColumn dc in dtTemp.Columns)

{

//Response.Write(dc.ColumnName + "<BR/>");

}

else

{

Response.Write("No data returned from the DataTable");

}

GridView2.DataSource = dtTemp;

GridView2.DataBind();

}

To download the sample code click here. I hope this will help you out.

Wednesday, February 20, 2013

C# - Remove Columns that contains null values in Data Table

Source Code:

Cs Code:

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