MDAC 2.5 SDK - ADO

OpenSchema Method Example (VJ++)

See Also

This example uses the OpenSchema method to display the name and type of each table in the Pubs database.

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

public class OpenSchemaX
{
 // The main entry point of the application.

public static void main (String[] args)
{
   OpenSchemaX();
   OpenSchemaX2();
   System.exit(0);
}

// OpenSchemaX Function
static void OpenSchemaX()
{
   // Define ADO Objects
   Connection cnn1 = null;
   Recordset rstSchema = null;

   //  Declarations
   String strCnn;
   BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
   int intDisplayRecords = 5;
   int intRecordCount = 0;

   try
   {

      cnn1 = new Connection();
      strCnn = "Provider = Microsoft.Jet.OLEDB.4.0;" +
         "Data Source=C:\\Program Files\\Microsoft " +
         "Office\\Office\\Samples\\Northwind.mdb;" +
         "User Id=admin;Password=;";
      cnn1.open(strCnn);
      rstSchema = cnn1.openSchema(AdoEnums.Schema.TABLES);

      while (!rstSchema.getEOF())
      {

         System.out.println("Table Name: " + 
            chema.getField("TABLE_NAME").getString()+"\n"+
            "Table Type: " + 
            chema.getField("TABLE_TYPE").getString()+"\n");
         intRecordCount++;
         if ( intRecordCount == intDisplayRecords)
         {
            System.out.println("Press <Enter> to continue..");
            in.readLine();
            intRecordCount = 0;
         }
         rstSchema.moveNext();

      }
      System.out.println("Press <Enter> to continue..");
      in.readLine();
      // Cleanup objects before exit
      rstSchema.close();
      cnn1.close();

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

      // As passing a Recordset, check for null pointer first.
      if(rstSchema != null)
      {
         PrintProviderError(rstSchema.getActiveConnection());
      }
      else
      {
         System.out.println("Exception: " + ae.getMessage());
      }
   }
   // System read requires this catch.
   catch(java.io.IOException je)
   {
      PrintIOError(je);
   }
}

// OpenSchemaX2 Function

static void OpenSchemaX2()
{
   // Define ADO Objects
   Connection cnn2 = null;
   Recordset rstSchema = null;

   // Declarations
   String strCnn;
   BufferedReader in = 
      new BufferedReader(new InputStreamReader(System.in));
   int intDisplayRecords = 5;
   int intRecordCount = 0;

   try
   {
      cnn2 = new Connection();
      strCnn = "Provider = Microsoft.Jet.OLEDB.4.0;" +
         "Data Source=C:\\Program Files\\Microsoft " +
         "Office\\Office\\Samples\\Northwind.mdb;" +
         "User Id=admin;Password=;";
      cnn2.open(strCnn);

      Variant[] va = new Variant[4];
      va[0] = new Variant();
      va[1] = new Variant();
      va[2] = new Variant();
      va[3] = new Variant("VIEW");
      rstSchema = cnn2.openSchema(AdoEnums.Schema.TABLES,(Object[])va);

      while (!rstSchema.getEOF())
      {
         System.out.println("Table Name: " + 
            rstSchema.getField("TABLE_NAME").getString()+"\n"+
            "Table Type: " + 
            rstSchema.getField("TABLE_TYPE").getString()+"\n");
         intRecordCount++;
         if ( intRecordCount == intDisplayRecords)
         {
            System.out.println("Press <Enter> to continue..");
            in.readLine();
            intRecordCount = 0;
         }
         rstSchema.moveNext();

      }
      System.out.println("Press <Enter> to continue..");
      in.readLine();
      // Cleanup Objects before exit.
      rstSchema.close();
      cnn2.close();

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

      // As passing a Recordset, check for null pointer first.
      if(rstSchema != null)
      {
         PrintProviderError(rstSchema.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");
   }
}