Prepared Property Example (VJ++)

 

This example demonstrates the Prepared property by opening two Command objects—one prepared and one not prepared.

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

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

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

   // PreparedX function

   static void PreparedX()
   {
      // Define string variables.
      String strCnn = "Provider='sqloledb';Data Source='MySqlServer';"
            + "Initial Catalog='Pubs';Integrated Security='SSPI';";
      String strCmd = "SELECT title, type FROM Titles ORDER BY type";

      // Define ADO Objects.
      Connection cnConn1 = null;
      Command cmd1 = null;
      Command cmd2 = null;

      // Declarations.
      BufferedReader in = 
         new BufferedReader (new InputStreamReader(System.in));
      long timeStart;
      long timeEnd;
      float timeNotPrepared ;
      float timePrepared;
      int   intLoop;
      String strTemp;

      try
      {
         // Open a connection.
         cnConn1 = new Connection();
         cnConn1.open(strCnn);

         // Create two command objects for the same
         // command - one prepared and one not prepared.
         cmd1 = new Command();
         cmd1.setActiveConnection(cnConn1);
         cmd1.setCommandType(AdoEnums.CommandType.TEXT);
         cmd1.setCommandText(strCmd);

         cmd2 = new Command();
         cmd2.setActiveConnection(cnConn1);
         cmd2.setCommandType(AdoEnums.CommandType.TEXT);
         cmd2.setCommandText(strCmd);
         cmd2.setPrepared(true);

         // Set a timer, then execute the unprepared
         // command 20 times.
         timeStart = System.currentTimeMillis();
         for ( intLoop = 0; intLoop < 20; intLoop++)
            cmd1.execute();
         timeEnd = System.currentTimeMillis();
         timeNotPrepared =(float)(timeEnd - timeStart)/1000f;

         // Reset the timer, then execute the prepared
         // command 20 times.
         timeStart = System.currentTimeMillis();
         for ( intLoop = 0; intLoop < 20; intLoop++)
            cmd2.execute();
         timeEnd = System.currentTimeMillis();
         timePrepared =(float)(timeEnd - timeStart)/1000f;

         // Display performance results.
         System.out.println("\nPerformance Results:");
         System.out.println("\n\tNot Prepared: " + timeNotPrepared + 
            " seconds");
         System.out.println("\n\tPrepared: " + timePrepared + 
            " seconds");
         System.out.println("\n\nPress <Enter> to continue..");
         in.readLine();

      }
      catch( AdoException ae )
      {
         // Notify user of any errors that result from ADO.

         // As passing a Connection, check for null pointer first.
         if (cnConn1!= null)
         {
            PrintProviderError(cnConn1);
         }
         else
         {
            System.out.println("Exception: " + ae.getMessage());
         }
      }

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

      finally
      {
         // Cleanup objects before exit.   
         if (cnConn1 != null)
            if (cnConn1.getState() == 1)
               cnConn1.close();
      }

   }

   // PrintProviderError Function

   static void PrintProviderError( Connection Cnn1 )
   {
      // Print Provider errors from Connection object.
      // ErrItem is an item object in the Connections 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");
   }
}
// EndPreparedJ

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