Open and Close Methods Example (VJ++)

 

This example uses the Open and Close methods on both Recordset and Connection objects that have been opened.

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

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

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

   // OpenX function

   static void OpenX()
   {

      // Define ADO Objects.
      Connection cnConn1 = null;
      Recordset rstEmployees = null;

      // Declarations.
      BufferedReader in = 
         new BufferedReader (new InputStreamReader(System.in));
      String strCnn = "Provider='sqloledb';Data Source='MySqlServer';"
                  + "Initial Catalog='Pubs';Integrated Security='SSPI';";
      Variant varDate;
      String strHDate;

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

         // Open Employees table.
         rstEmployees = new Recordset();
         rstEmployees.setCursorType(AdoEnums.CursorType.KEYSET);
         rstEmployees.setLockType(AdoEnums.LockType.OPTIMISTIC);
         rstEmployees.open("Employee", cnConn1,
                    AdoEnums.CursorType.KEYSET,
                    AdoEnums.LockType.OPTIMISTIC,
                    AdoEnums.CommandType.TABLE);

         // Assign the first employee record's hire date
         // to a variable, then change the hire date.
         varDate = rstEmployees.getField("hire_date").getOriginalValue();
         System.out.println("Original data\n");
         System.out.println("\tName - Hire Date");
         strHDate = rstEmployees.getField("hire_date").getString();
         strHDate = strHDate.substring(5,7) + "/" + 
            strHDate.substring(8,10)
             + "/" + strHDate.substring(2,4);
         System.out.println("\t" + 
            rstEmployees.getField("fName").getString()+ " "
             + rstEmployees.getField("lName").getString()+ " - "
             + strHDate);
         System.out.println("\nPress <Enter> to continue..");
         in.readLine();
         rstEmployees.getField("hire_date").setString("1/1/1900");
         rstEmployees.update();
         System.out.println("Changed data\n");
         System.out.println("\tName - Hire Date");
         strHDate = rstEmployees.getField("hire_date").getString();
         strHDate = strHDate.substring(5,7) + "/" + 
            strHDate.substring(8,10)
             + "/" + strHDate.substring(0,4);
         System.out.println("\t" + 
            rstEmployees.getField("fName").getString()+ " "
             + rstEmployees.getField("lName").getString()+ " - "
             + strHDate);
         System.out.println("\nPress <Enter> to continue..");
         in.readLine();

         // Requery Recordset and reset the hire date.
         rstEmployees.requery();
         rstEmployees.getField("hire_date").setValue(varDate);
         rstEmployees.update();
         System.out.println("Data after reset\n");
         System.out.println("\tName - Hire Date");
         strHDate = rstEmployees.getField("hire_date").getString();
         strHDate = strHDate.substring(5,7) + "/" + 
            strHDate.substring(8,10)
             + "/" + strHDate.substring(2,4);
         System.out.println("\t" + 
            rstEmployees.getField("fName").getString()+ " "
             + rstEmployees.getField("lName").getString()+ " - "
             + strHDate);
         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 (rstEmployees != null)
         {
            PrintProviderError(rstEmployees.getActiveConnection());
         }
         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 (rstEmployees != null)
            if (rstEmployees.getState() == 1)
               rstEmployees.close();
         // 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");
   }
}
// EndOpenJ

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