Export database to excel file

by the3factory 3/11/2008 6:15:00 PM

First of all, I need to give some credit to Mahesh Chand for providing me with an excellent basis to export data to excel.

What does this code do:
As the title says, this code is capable of extracting all tables and it's data from any given database and export it to Excel! Every table gets it's own worksheet. I was searching the net for a program like this, but I didn't come accross any (free) versions. So I decided to write it myself.

Using the code

To get this code to work, you need to add a reference to Excel.dll by using Add Reference on the project and selecting Microsoft Excel 9.0 (or 10.0) Object Library from the COM tab on the Add Reference dialog.

And then import the following namespace:

            Imports System.Runtime.InteropServices.Marshal

Now add the following class to your project:

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Private Sub create(ByVal sDatabaseName As String)
Dim dsTables As DataSet = New DataSet
'Get all Tables from database
dsTables = getAllTables(sDatabaseName)
'Create Excel Application, Workbook, and WorkSheets
Dim xlExcel As New Excel.Application
Dim xlBooks As Excel.Workbooks
Dim xlBook As Excel.Workbook
Dim tblSheet As Excel.Worksheet
Dim xlCells As Excel.Range
Dim sFile As String
'File name for the excel files
File = Server.MapPath(sDatabaseName & "_data.xls")
xlExcel.Visible = False : xlExcel.DisplayAlerts = False
xlBooks = xlExcel.Workbooks
xlBook = xlBooks.Add
For i As Integer = 0 To dsTables.Tables.Count - 1
tblSheet = xlBook.Worksheets.Add
tblSheet.Name = dsTables.Tables(i).TableName
xlCells = tblSheet.Cells
'Fill all cells with data 
GenerateExcelFile(dsTables.Tables(i), xlCells)
Next
'Remove initial excel sheets. Within a try catch because the database 
'could be empty (a workbook without worksheets is not allowed)
Try
Dim SheetCount As Integer = xlExcel.Sheets.Count
CType(xlExcel.Sheets(SheetCount - 0), Excel.Worksheet).Delete()
CType(xlExcel.Sheets(SheetCount - 1), Excel.Worksheet).Delete()
CType(xlExcel.Sheets(SheetCount - 2), Excel.Worksheet).Delete()
Catch ex As Exception
End Try
'Save the excel file
xlBook.SaveAs(sFile)
'Make sure all objects are disposed
xlBook.Close()
xlExcel.Quit()
ReleaseComObject(xlCells)
ReleaseComObject(tblSheet)
ReleaseComObject(xlBook)
ReleaseComObject(xlBooks)
ReleaseComObject(xlExcel)
xlExcel = Nothing
xlBooks = Nothing
xlBook = Nothing
tblSheet = Nothing
xlCells = Nothing
'Let the Garbage Collector know it can get to work
GC.Collect()
'Export Excel for download
Try
HttpContext.Current.Response.ContentType = "application/octet-stream"
HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment; filename=" + System.IO.Path.GetFileName(sFile))
HttpContext.Current.Response.Clear()
HttpContext.Current.Response.WriteFile(sFile)
HttpContext.Current.Response.End()
Catch ex As Exception
'An exception will be thrown, but can just be ignored
End Try
End Sub

To generate the individual sheets, the following Sub is used:

Private Sub GenerateExcelFile(ByRef table As DataTable, ByVal xlCells As Excel.Range)
Dim dr As DataRow, ary() As Object
Dim iRow As Integer, iCol As Integer
'Output Column Headers
For iCol = 0 To table.Columns.Count - 1
xlCells(1, iCol + 1) = table.Columns(iCol).ToString
xlCells(1).EntireRow.Font.Bold = True
Next
'Output Data
For iRow = 0 To table.Rows.Count - 1
dr = table.Rows.Item(iRow)
ary = dr.ItemArray
For iCol = 0 To UBound(ary)
xlCells(iRow + 2, iCol + 1) = ary(iCol).ToString
Response.Write(ary(iCol).ToString & vbTab)
Next
Next
xlCells.Columns.AutoFit()
End Sub

And now the trick to getting all tables and data from a database:

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Public database as String
Public ReadOnly Property getAllTables(ByVal sDB As String) As DataSet
Get
database = sDB
Dim m_dshelp As DataSet = New DataSet
getRequestedAllTables(m_dshelp)
Return m_dshelp
End Get
End Property
Private Function getRequestedAllTables(ByRef p_dataset As DataSet) As Boolean
'Retrieve all tablenames from the database:
Dim sSQL As String
Dim dsTables As DataSet = New DataSet
sSQL = "SELECT [TableName] = so.name, [RowCount] = MAX(si.rows) " & _
"FROM sysobjects so, sysindexes si " & _
"WHERE so.xtype = 'U' AND si.id = OBJECT_ID(so.name) AND si.rows > 0 " & _
"GROUP BY so.name " & _
"ORDER BY 2 DESC"
getData(sSQL, "Tables", dsTables)
'Loop thrue all tables and do a SELECT *. Then add them to the dataset
For i As Integer = 0 To dsTables.Tables(0).Rows.Count - 1
sSQL = "SELECT * FROM " & dsTables.Tables(0).Rows(i).Item(0)
getData(sSQL, dsTables.Tables(0).Rows(i).Item(0), p_dataset)
Next
End Function
Private Function getData(ByVal p_sql As String, ByVal p_table As String, ByRef pdataset As DataSet) As Boolean
Dim objDataAdapter As SqlDataAdapter
Dim objcommand As SqlCommand
objcommand = New SqlCommand(p_sql, getConnection)
objDataAdapter = New SqlDataAdapter(objcommand)
objDataAdapter.Fill(pdataset, p_table)
End Function
Private Function getConnection() As SqlConnection
If (ConfigurationManager.AppSettings("SQLPW") <> "") Then
getConnection = New SqlConnection("Server=" & _
ConfigurationManager.AppSettings("SQLserver") & ";password=" & _
ConfigurationManager.AppSettings("SQLPW") & "; user=" & _
ConfigurationManager.AppSettings("SQLUser") & ";database=" & database)
Else
getConnection = New SqlConnection("Data Source=" & _
ConfigurationManager.AppSettings("SQLserver") & ";Initial Catalog=" & _
database & ";Integrated Security=True")
End If
End Function