MDAC 2.5 SDK - ADO

Source Property Example (VJ++)

See Also

This example demonstrates the Source property by opening three Recordset objects based on different data sources.

import java.io.*;
import com.ms.wfc.data.*;

public class SourceX
{
   // The main entry point of the application.
   public static void main (String[] args)
   {
      SourceX();
      System.exit(0);
   }
   // SourceX Function
   static void SourceX()
   {
      // Define string variables.
      String strCnn = "Provider=sqloledb;Data Source=srv;" +
                  "Initial Catalog=Pubs;User Id=sa;Password=;";
      String strSQL = "SELECT title_ID AS TitleID, title AS Title,"+
                "publishers.pub_id AS PubID, pub_name AS PubName "+
                "FROM publishers INNER JOIN Titles "+
                "ON publishers.pub_id=Titles.pub_id "+
                "ORDER BY Title";

      // Define ADO Objects.
      Connection cnn1 = null;
      Recordset rstTitles = null;
      Recordset rstPublishers = null;
      Recordset rstPublishersDirect = null;
      Recordset rstTitlesPublishers = null;
      Command cmdSQL = null;

      // Declarations.
      BufferedReader in = 
         new BufferedReader(new InputStreamReader(System.in));

      try
      {
         // Open a connection.
         cnn1 = new Connection();
         cnn1.open(strCnn);

         // Open a recordset based on a command object.
         cmdSQL = new Command();
         cmdSQL.setActiveConnection(cnn1);
         cmdSQL.setCommandText("Select title,type,pubdate " +
             "FROM Titles ORDER BY title");

         rstTitles = new Recordset();
         rstTitles = cmdSQL.execute();

         // Open a recordset based on a table.
         rstPublishers = new Recordset();
         rstPublishers.open("publishers", strCnn, 
            AdoEnums.CursorType.FORWARDONLY, AdoEnums.LockType.READONLY, 
            AdoEnums.CommandType.TABLE);

         // Open a recordset based on a table.
         rstPublishersDirect = new Recordset();
         rstPublishersDirect.open("publishers", strCnn, 
            AdoEnums.CursorType.FORWARDONLY, AdoEnums.LockType.READONLY, 
            AdoEnums.CommandType.TABLEDIRECT);

         // Open a recordset based on an SQL String.
         rstTitlesPublishers = new Recordset();

         rstTitlesPublishers.open(strSQL, strCnn, 
            AdoEnums.CursorType.FORWARDONLY, AdoEnums.LockType.READONLY, 
            AdoEnums.CommandType.TEXT);

         // Use Source property to display the source of each recordset.
         System.out.println("\nrstTitles source: \n"+
            rstTitles.getSource());
         System.out.println("\nrstPublishers source: \n"+
            rstPublishers.getSource());
         System.out.println("\nrstPublishersDirect source:\n" +
            rstPublishersDirect.getSource() );
         System.out.println("\nrstTitlesPublishers source: \n" +
            rstTitlesPublishers.getSource());

         // Cleanup Objects before exit.
         rstTitles.close();
         rstPublishers.close();
         rstPublishersDirect.close();
         rstTitlesPublishers.close();
         cnn1.close();

         System.out.println("\n\nPress <Enter> to continue..");
         in.readLine();
      }
      catch(AdoException ae)
      {
         // Notify the user of any errors that result from ADO.

         // As passing a recordset, check for null pointer first.

         if(rstPublishers != null)
         {
            PrintProviderError(rstPublishers.getActiveConnection());
         }
         else if(rstPublishersDirect != null)
         {
            PrintProviderError(
               rstPublishersDirect.getActiveConnection());
         }
         else if(rstTitles != null)
         {
            PrintProviderError(rstTitles.getActiveConnection());
         }
         else if(rstTitlesPublishers != null)
         {
            PrintProviderError(
               rstTitlesPublishers.getActiveConnection());
         }
         else
            System.out.println("Exception: " + ae.getMessage());

      }
      // System read requires this catch.
      catch(java.io.IOException je)
      {
         PrintIOError(je);
      }

   }
   // PrintProviderError Function

   static void PrintProviderError( Connection Cnn1 )
   {
      // Print Provider errors from Connection object.
      // ErrItem is an item object in the Connection’s Errors collection.
      com.ms.wfc.data.Error  ErrItem = null;
      long nCount = 0;
      int  i      = 0;

      nCount = Cnn1.getErrors().getCount();

      // If there are any errors in the collection, print them.
      if( nCount > 0);
      {
         // Collection ranges from 0 to nCount - 1
         for (i = 0; i< nCount; i++)
         {
            ErrItem = Cnn1.getErrors().getItem(i);
            System.out.println("\t Error number: " + ErrItem.getNumber()
               + "\t" + ErrItem.getDescription() );
         }
      }

   }

   // PrintIOError Function

   static void PrintIOError( java.io.IOException je)
   {
      System.out.println("Error \n");
      System.out.println("\tSource = " + je.getClass() + "\n");
      System.out.println("\tDescription = " + je.getMessage() + "\n");
   }
}