Introduction:
In this article I will explain how to remove duplicate records from datatable or dataset in asp.net.
My
data appears like this with duplicate records but in one situation I
got requirement like to display only unique records of data to achieve
this I made some code changes in code behind for that check below code
In this article I will explain how to remove duplicate records from datatable or dataset in asp.net.
Description:
In previous posts I explained many articles regarding Asp.net, Gridview, Ajax, JQuery and many more. During write articles on those concepts generally we bind data to datatable or dataset that data contains duplicate records of data also that would be like this
In previous posts I explained many articles regarding Asp.net, Gridview, Ajax, JQuery and many more. During write articles on those concepts generally we bind data to datatable or dataset that data contains duplicate records of data also that would be like this
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Write the following code in your aspx page
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Delete Duplicate Records of Data</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:GridView ID="gvDetails" runat="server"/>
</div>
</form>
</body>
</html>
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After completion of aspx page design add following namespaces in code behind
C# Code
using System;
using System.Collections;
using System.Data;
using System.Data.SqlClient;
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After add namespace write the following code
protected void Page_Load(object sender, EventArgs e)
{
if(!IsPostBack)
{
SqlConnection con = new SqlConnection("Data Source=SureshDasari; Initial Catalog=MySampleDB; Integrated Security=true");
con.Open();
SqlCommand cmd = new SqlCommand("select * from SampleTable", con);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds,"UserDetails");
DataTable dt = ds.Tables["UserDetails"];
RemoveDuplicateRows(dt, "UserName"); // Here UserName is Column name of table
gvDetails.DataSource = ds;
gvDetails.DataBind();
}
}
// This method is used to delete duplicate rows of table
public DataTable RemoveDuplicateRows(DataTable dTable, string colName)
{
Hashtable hTable = new Hashtable();
ArrayList duplicateList = new ArrayList();
foreach (DataRow dtRow in dTable.Rows)
{
if (hTable.Contains(dtRow[colName]))
duplicateList.Add(dtRow);
else
hTable.Add(dtRow[colName], string.Empty);
}
foreach (DataRow dtRow in duplicateList)
dTable.Rows.Remove(dtRow);
return dTable;
}
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VB.NET Code
Imports System.Collections
Imports System.Data
Imports System.Data.SqlClient
Partial Class Default
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
If Not IsPostBack Then
Dim con As New SqlConnection("Data Source=SureshDasari; Initial Catalog=MySampleDB; Integrated Security=true")
con.Open()
Dim cmd As New SqlCommand("select * from SampleTable", con)
Dim da As New SqlDataAdapter(cmd)
Dim ds As New DataSet()
da.Fill(ds, "UserDetails")
Dim dt As DataTable = ds.Tables("UserDetails")
RemoveDuplicateRows(dt, "UserName")
' Here UserName is Column name of table
gvDetails.DataSource = ds
gvDetails.DataBind()
End If
End Sub
Public Function RemoveDuplicateRows(ByVal dTable As DataTable, ByVal colName As String) As DataTable
Dim hTable As New Hashtable()
Dim duplicateList As New ArrayList()
For Each dtRow As DataRow In dTable.Rows
If hTable.Contains(dtRow(colName)) Then
duplicateList.Add(dtRow)
Else
hTable.Add(dtRow(colName), String.Empty)
End If
Next
For Each dtRow As DataRow In duplicateList
dTable.Rows.Remove(dtRow)
Next
Return dTable
End Function
End Class
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Now run in your application and check output that would be like this
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