Navision Database Access via C/ODBC WebService/ASP.NET Application

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Navision (former Navision Attain), together with Microsoft Great Plains, Axapta, Solomon, Microsoft CRM, and Microsoft RMS are now supported by Microsoft Business Solutions. Navision has various customization options. Today, you will learn about a simple case of using a C/ODBC driver. This driver and technology allow you to work with a Native or C/SIDE Navision database. Navision also is available on Microsoft SQL Server; in this case, you use traditional Microsoft technologies, such as an OLEDB or MS SQL Server driver to open a ADO.NET connection. The goal is to help IT departments support and tune Navision with in-house expertise and skills. The topic of this article is Navision Attain database access through Webservice, connected to Navision via a C/ODBC-based Linked Server—the mechanism available in MS SQL Server 2000—and transfer the results to an ASP.NET application. The goal will be ASPX page accessing Navision Customers.

To begin:

1. In your case, you will use Navision Attain 3.6 with Navision Database Server, Navision Application Server, and Navision Client. These components are installed on Windows XP. You also need to install the C/ODBC component from the Navision Attain CD.
2. Now, create an ODBC DSN for Navision data access. Select Control Panel -> Administrative Tools -> Data Sources (ODBC). Then, select the System DSN tab and press the Add button. You’ll use a C/ODBC 32-bit data access driver. Name it Data Source Name Navision; leave Connection Local. As to the database (Database button), select \Program Files\Navision Attain\Client\database.fdb (demo database). Then, click the Company button; use the CRONUS demo company. It is important for C/SIDE correct database access to set up the proper options for the C/ODBC connection. Press the Options button and look at the options available. You’ll need the Identifiers parameter; it defines the identifiers types that will be transferred to the client application. To work correctly with MS SQL Server 2000 with C/ODBC source, you need to use these types: "a-z,A-Z,0-9,_". Now, DNS is done. Create Linked Server.
3. Open MS SQL Server Enterprise Manager. Open a server tree for the server that you plan to use. For this server, open the Security folder and Lined Servers. With a right-click, select New Linked Server in the context menu. In the dialog box opened in Provider Name, select Microsoft OLE DB Provider for ODBC Drivers. Name your Linked Server NAVISION. In the Data Source string, enter the ODBC DSN name: NAVISION in your case. Linked Server is ready! Now, select the tables list and look at the data from Navision Attain database.
4. Next, you need to create a small stored procedure for the sales data selection. Here is the text of the procedure:

   SET ANSI_NULLS ON
   SET ANSI_WARNINGS ON
   GO
   
   CREATE PROCEDURE NavisionCustomers AS
   
   DBCC TRACEON(8765)
   SELECT No_, Name, Address, City, Contact
   FROM OPENQUERY(NAVISION, 'SELECT * FROM Customer')
   
   RETURN
   

   Let me clarify some points here. The TRACEON(8765) directive allows you to work with the data of variable length, returned by the C/ODBC driver. Without it, you cannot select Navision tables fields; you will have these errors:

   OLE DB error trace [Non-interface error:  Unexpected data
      length returned for the column:  ProviderName='MSDASQL',
      TableName='[MSDASQL]', ColumnName='Ship_to_Filter',
      ExpectedLength='250', ReturnedLength='1'].
   Server: Msg 7347, Level 16, State 1, Line 1
   OLE DB provider 'MSDASQL' returned an unexpected data length
      for the fixed-length column '[MSDASQL].Ship_to_Filter'.
      The expected data length is 250, while the returned
      data length is 1.
   

   The OPENQUERY command opens a linked server, gives it an execution request, and returns the selected record set. The ANSI_NULLS and ANSI_WARNINGS directives are required; they provide the possibility of the execution for heterogeneous requests. To test the procedure, you can give its name in MS SQL Query Analyzer: EXEC NavisionCustomers

5. Now, you need to create an ASP.NET application. Use the free RAD environment ASP.NET WebMatrix. You can get information and download it at http://asp.net/webmatrix. You need .NET SDK 1.1 installed before WebMatrix installation.
6. Launch WebMatrix and then select XML Web Service creation in the Wizard window. Leave all the parameters default; just change the file name to NavisionItems, the class name to NavisionItems, and Namespace as NavDemo. Midify the WebService code as below (change connection string to actual names):

   <%@ WebService language="VB" class="NavisionItems" %>
   
   Imports System
   Imports System.Web.Services
   Imports System.Xml.Serialization
   
   Public Class NavisionItems
   
    Function GetNavisionItems() As System.Data.DataSet
   Dim connectionString As String = "server='(local)';
      trusted_connection=true; database='Alba'"
   Dim dbConnection As System.Data.IDbConnection = New
      System.Data.SqlClient.SqlConnection(connectionString)
   
   Dim queryString As String = "EXEC NavisionItems"
   Dim dbCommand As System.Data.IDbCommand = New
      System.Data.SqlClient.SqlCommand
   dbCommand.CommandText = queryString
   dbCommand.Connection = dbConnection
   
   Dim dataAdapter As System.Data.IDbDataAdapter = New
      System.Data.SqlClient.SqlDataAdapter
   dataAdapter.SelectCommand = dbCommand
   
   Dim dataSet As System.Data.DataSet = New System.Data.DataSet
   dataAdapter.Fill(dataSet)
   
   Return dataSet
   End Function
   End Class
   

7. Now, create an ASP.NET application that will show the result set returned by the WebService. Create an empty ASP.NET page with the WebMatrix wizard. Name it TestNavisionItems.aspx. Place these controls on the page: DataGrid and Button. Then, switch to the Code mode and, from the Tools menu, launch WebService Proxy Generator. In the following dialog screen, specify http://localhost/NavisionItems.asmx as the WSDL URL (if you launch WebService on a different host or the Web server works through a different port, change the parameters accordingly).
   

   Note: At this time, if you are deploying WebService on the local machine, using the WebMatrix web server Cassini, it must be running already. Define Namespace as NavDemo and execute code generation. Next, define a Button handler:

   Sub Button1_Click(sender As Object, e As EventArgs)
      ' Insert page code here
      '
      Dim wsProxy As New NavDemo.NavisionItems()
   
      DataGrid1.DataSource = wsProxy.GetNavisionItems()
      DataGrid1.DataBind()
   End Sub
   

8. Next launch your page, press the button on the front, and you are getting Navision Items Navision Items!

About the Author

Boris Makushkin is the Lead Software Developer with Alba Spectrum Technologies (http://www.albaspectrum.com), a USA nationwide Navision Customization company. Boris can be reached at help@albaspectrum.com or 1-630-961-5918.