MDAC 2.5 SDK - ADO

StayInSync Property Example (VJ++)

See Also

This example demonstrates how the StayInSync property facilitates accessing rows in a hierarchical Recordset.

The outer loop displays each author's first and last name, state, and identification. The appended Recordset for each row is retrieved from the Fields collection and automatically assigned to rstTitleAuthor by the StayInSync property whenever the parent Recordset moves to a new row. The inner loop displays four fields from each row in the appended recordset.

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

public class StayInSyncX
{
    // The main entry point for the application.

   public static void main (String[] args)
   {
      StayInSyncX();
      System.exit(0);
   }

   // StayInSyncX function

   static void StayInSyncX()
   {

      // Define ADO Objects.
      Connection cnConn1 = null;
      Recordset rstAuthors = null;
      Recordset rstTitleAuthor = null;

      // Declarations.
      BufferedReader in = new 
         BufferedReader (new InputStreamReader(System.in));
      String strCnn = "DSN=Pubs;Provider=MSDataShape;" + 
         "Data Provider=MSDASQL;uid=sa;pwd=;";

      try
      {
         cnConn1 = new Connection();
         cnConn1.open(strCnn);
         rstAuthors = new Recordset();
         rstAuthors.setStayInSync(true);
         rstAuthors.open("SHAPE  {select * from Authors} " +
                "APPEND ({select * from titleauthor}" +
                "RELATE au_id TO au_id) AS chapTitleAuthor",
               cnConn1,
               AdoEnums.CursorType.STATIC,
               AdoEnums.LockType.READONLY,
               AdoEnums.CommandType.TEXT);

         Variant varRstTitleAuthor = rstAuthors.getFields().
            getItem("chapTitleAuthor").getValue();
         rstTitleAuthor =new Recordset(varRstTitleAuthor.toObject());
         int intCount =0;
         while(!rstAuthors.getEOF())
         {
            System.out.println("\n" +
               rstAuthors.getField("au_fname").getString() + " " +
               rstAuthors.getField("au_lname").getString() + " " +
                rstAuthors.getField("state").getString() + " " +
                rstAuthors.getField("au_id").getString());
            while(!rstTitleAuthor.getEOF())
            {
               System.out.println(rstTitleAuthor.getField(0).
                  getString() + " " +
                  rstTitleAuthor.getField(1).getString() + " " +
                  rstTitleAuthor.getField(2).getString() + " " +
                  rstTitleAuthor.getField(3).getString());
               rstTitleAuthor.moveNext();
            }
            if(++intCount % 5 == 0)
            {
               System.out.println("\nPress <Enter> to continue..");
               in.readLine();
            }
            rstAuthors.moveNext();
         }
         // Cleanup objects before exit.
         rstTitleAuthor.close();
         rstAuthors.close();
         cnConn1.close();

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

         // As passing a Recordset, check for null pointer first.
         if (rstAuthors != null)
         {
            PrintProviderError(rstAuthors.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("\t Source: " + je.getClass() + "\n");
      System.out.println("\t Description: "+ je.getMessage() + "\n");
   }
}