Dynamically changing MySQL connection string to Crystal Reports - mysql

Question

I am using CrystalReportViewer and CrystalReportSource to load and display an .rpt file in my application.
The situation I have is this:
Say a person created a Crystal Reports report outside of my application and set its datasource to database. Then I use that .rpt file in my application, but I need to bind it to a different database (identical to the original one in terms of table structure and column names but with a different connection string and user name and password).
How do I do that in VB.NET code?
Currently I load the report using:
Public Function SetReportSource(ByVal RptFile As String) As ReportDocument
Try
Dim crtableLogoninfo As New TableLogOnInfo()
Dim crConnectionInfo As New ConnectionInfo()
Dim CrTables As Tables
Dim CrTable As Table
If System.IO.File.Exists(RptFile) Then
Dim crReportDocument As New ReportDocument()
crReportDocument.Load(RptFile)
With crConnectionInfo
.ServerName = "DRIVER={MySQL ODBC 5.1 Driver};SERVER=localhost;Port=3306;UID=root;"
.DatabaseName = gDatabaseName
.UserID = gServerUser
.Password = gServerPassword
End With
CrTables = crReportDocument.Database.Tables
For Each CrTable In CrTables
CrTable.ApplyLogOnInfo(crtableLogoninfo)
CrTable.LogOnInfo.ConnectionInfo.ServerName = crConnectionInfo.ServerName
CrTable.LogOnInfo.ConnectionInfo.DatabaseName = crConnectionInfo.DatabaseName
CrTable.LogOnInfo.ConnectionInfo.UserID = crConnectionInfo.UserID
CrTable.LogOnInfo.ConnectionInfo.Password = crConnectionInfo.Password
'Apply the schema name to the table's location
CrTable.Location = gDatabaseName & "." & CrTable.Location
Next
crReportDocument.VerifyDatabase()
SetReportSource = crReportDocument
Else
MsgBox("Report file not found...", MsgBoxStyle.Critical, proTitleMsg)
End If
Catch ex As Exception
System.Windows.Forms.MessageBox.Show("Error Found..." & vbCrLf & "Error No : " & Err.Number & vbCrLf & "Description :" & Err.Description & vbCrLf & vbCrLf & "Line no : " & Err.Erl & vbCrLf & "Procedure name : SetReportSource" & vbCrLf & "Module name : GeneralFunctions", proTitleMsg)
End Try
End Function

Answer 1

This is how I did it. I was using Oracle with ODBC on ASP.NET, but you should be able to do the same with MySQL and ODBC:
As part of the legacy application upgrade I've been doing, I decided to move the Crystal Reports to a Web application rather that having the users access them directly on Crystal Reports XI via Citrix, which has been the method they have been using.  This has several advantages, the primary one being speed.  One problem that plagued me was how to change the logon information at run-time, such that the application would automatically point at the correct Oracle database (development, test, or production) based on which server the report was being accessed from.
The solution I found was to set up the Oracle Database connection as a DSN in ODBC, and connecting to the ODBC DSN rather than using the Oracle Client directly.  This is not the only way to do it, but it seems to be the best way for my purposes.
In the code-behind file for the page that contains the Crystal Reports Viewer, I placed the following code that handles the same event that renders the viewer.
Protected Sub btnGenerate_Click(sender As Object, e As System.EventArgs) Handles btnGenerate.Click
Dim connInfo As New ConnectionInfo
Dim rptDoc As New ReportDocument
' setup the connection
With connInfo
.ServerName = "oracledsn" ' ODBC DSN in quotes, not Oracle server or database name
.DatabaseName = "" ' leave empty string here
.UserID = "username" ' database user ID in quotes
.Password = "password"  'database password in quotes
End With
' load the Crystal Report
rptDoc.Load(Server.MapPath(Utilities.AppSettingsFunction.getValue("ReportFolder") & ddlReports.SelectedValue))
' add required parameters
If pnlstartdates.Visible Then
rptDoc.SetParameterValue("REPORT_DATE", txtSingleDate.Text)
End If
' apply logon information
For Each tbl As CrystalDecisions.CrystalReports.Engine.Table In rptDoc.Database.Tables
Dim repTblLogonInfo As TableLogOnInfo = tbl.LogOnInfo
repTblLogonInfo.ConnectionInfo = connInfo
tbl.ApplyLogOnInfo(repTblLogonInfo)
Next
' Set, bind, and display Crystal Reports Viewer data source
Session("rptDoc") = rptDoc
Me.CrystalReportViewer1.ReportSource = Session("rptDoc")
CrystalReportViewer1.DataBind()
UpdatePanel1.Update()
End Sub
The logon info above can easily be stored in web.config instead of hard-coding it as above.
Incidentally, I chose to put my Crystal Reports Viewer in an ASP.NET AJAX Update Panel, which is why the ReportSource of the viewer is stored in a Session variable.  If you choose to do this, the viewer must be databound in the Init event (not the Load event) to show up properly.
Protected Sub Page_Init(sender As Object, e As System.EventArgs) Handles Me.Init
If Not Page.IsPostBack Then
txtSingleDate.Text = Now.Date()
ElseIf Session("rptDoc") IsNot Nothing Then
Me.CrystalReportViewer1.ReportSource = Session("rptDoc")
CrystalReportViewer1.DataBind()
UpdatePanel1.Update()
End If
End Sub