OpenSchema Method Example (VJ++)

OpenSchema Method Example (VJ++)

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");
    }
}