compare the content of 2 gridviews in one aspx page - asp.net

Question

we need to compare the content of 2 identical gridviews and extract rows that differ in a third gridview, is this doable?
i tried a lot but faced no luck, please help me.
at our office we take daily backup of ASP.net application ms access backend
for the next few days we need to evaluate the changes made to records in the database tables
at the end of each day i want to compare 2 access databases first database is the backup of yesterday and second database is the backup of today
i thought of the following algorithm, please read carefully and tell me how to proceed to compare the datatables / gridviews
i need to display th rows / cells containing the differences / updates / deleted data
comparing two ms access backend databases of an asp.net web application

Answer 1

my team and myseld figured it out
Imports System.Data
Imports System.Data.OleDb
Partial Class MoKoTrack
Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim myDB = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|databaseName.mdb;Persist Security Info=True")
Session("CurrentDB") = myDB
myDB.open()
Dim mytables = myDB.GetOleDbSchemaTable(OleDbSchemaGuid.Primary_Keys, New Object() {})
Dim CurrentTable As String
For i = 1 To mytables.Rows.Count
CurrentTable = mytables.Rows(i - 1).Item(2).ToString
If CurrentTable.Contains("Backup") Then CompareTable(CurrentTable, mytables.Rows(i - 1).Item(3).ToString)
Next i
' Dim myGrid As New GridView
'myGrid.DataSource = mytables
'myGrid.DataBind()
'Me.Form.Controls.Add(myGrid)
'myDB.Close()
End Sub
Sub CompareTable(ByVal BackupTableName As String, ByVal myPrimKey As String)
Dim OriginalTable As New DataTable
Dim BackupTable As New DataTable
Dim ModificationsTable As New DataTable
Dim AddedTable As New DataTable
Dim DeletedTable As New DataTable
Dim myDB = Session("CurrentDB")
Dim FinalSQLString = "SELECT * FROM [" + BackupTableName + "]"
Dim myDBCommand = New OleDbCommand(FinalSQLString, myDB)
Dim myReader As IDataReader = myDBCommand.ExecuteReader()
BackupTable.Load(myReader)
Dim OriginalTableName = Left(BackupTableName, Len(BackupTableName) - 6)
Dim FinalSQLString2 = "SELECT * FROM [" + OriginalTableName + "]"
Dim myDBCommand2 = New OleDbCommand(FinalSQLString2, myDB)
'Generate a temporary reader to get the number of cases
Dim myReader2 As IDataReader = myDBCommand2.ExecuteReader()
OriginalTable.Load(myReader2)
Dim myPrimColumn(0) As DataColumn
myPrimColumn(0) = OriginalTable.Columns(myPrimKey)
OriginalTable.PrimaryKey = myPrimColumn
Dim myPrimColumn2(0) As DataColumn
myPrimColumn2(0) = BackupTable.Columns(myPrimKey)
BackupTable.PrimaryKey = myPrimColumn2
AddedTable = OriginalTable.Clone
DeletedTable = OriginalTable.Clone
ModificationsTable = OriginalTable.Clone
ModificationsTable.PrimaryKey = Nothing
Dim CurrentVal As String
For i = 0 To OriginalTable.Rows.Count - 1
CurrentVal = OriginalTable.Rows(i).Item(myPrimKey).ToString
Dim foundRow As DataRow = BackupTable.Rows.Find(CurrentVal)
If foundRow IsNot Nothing Then
For t = 0 To OriginalTable.Columns.Count - 1
If Not foundRow.Item(t).ToString = OriginalTable.Rows(i).Item(t).ToString Then
ModificationsTable.ImportRow(OriginalTable.Rows(i))
'ModificationsTable.Rows(ModificationsTable.Rows.Count - 1).Item(t) = ModificationsTable.Rows(ModificationsTable.Rows.Count - 1).Item(t) & "Modified"
ModificationsTable.ImportRow(foundRow)
End If
Next
Else
AddedTable.ImportRow(OriginalTable.Rows(i))
End If
Next
For i = 0 To BackupTable.Rows.Count - 1
CurrentVal = BackupTable.Rows(i).Item(myPrimKey).ToString
Dim foundRow As DataRow = OriginalTable.Rows.Find(CurrentVal)
If foundRow Is Nothing Then
DeletedTable.ImportRow(OriginalTable.Rows(i))
End If
Next
If AddedTable.Rows.Count > 0 Then
Dim myLabel As New Label
myLabel.Text = "<br/> The following records were added to table " & OriginalTableName & "<br/> <br/>"
Me.form1.Controls.Add(myLabel)
Dim myGrid As New GridView
myGrid.DataSource = AddedTable
myGrid.DataBind()
Me.form1.Controls.Add(myGrid)
End If
If ModificationsTable.Rows.Count > 0 Then
Dim myLabel As New Label
myLabel.Text = "<br/> The following records were modified in table " & OriginalTableName & "<br/> <br/>"
Me.form1.Controls.Add(myLabel)
Dim myGrid As New GridView
myGrid.DataSource = ModificationsTable
myGrid.DataBind()
Me.form1.Controls.Add(myGrid)
End If
If DeletedTable.Rows.Count > 0 Then
Dim myLabel As New Label
myLabel.Text = "<br/> The following records were deleted from table " & OriginalTableName & "<br/> <br/>"
Me.form1.Controls.Add(myLabel)
Dim myGrid As New GridView
myGrid.DataSource = DeletedTable
myGrid.DataBind()
Me.form1.Controls.Add(myGrid)
End If
End Sub
End Class

Answer 2

I usually compare it using LINQ
This will give you a head start
var SearchResults1 = from u in YourDB.YourUserTable1
orderby u.YourColumn
select u;
GridView1.DataSource = SearchResults1;
GridView1.DataBind();
var SearchResults2 = from u in YourDB.YourUserTable2
orderby u.YourColumn
select u;
GridView2.DataSource = SearchResults2;
GridView2.DataBind();
var SearchResults3 = from u1 in SearchResults2
where !(from u2 in SearchResults1
select u2.YourTablePrimaryKey).Contains(u1.YourTablePrimaryKey)
orderby u1.YourColumn
select u1;
GridView3.DataSource = SearchResults3;
GridView3.DataBind();
You can further elaborate SearchResults 3 if you want like comparing whats in SearchResults1 but not in SearchResults2 and vice versa