Find メソッドの例 (VJ++)

この例では、Recordset オブジェクトの Find メソッドを使って、Pubs データベースのビジネス タイトルを検索して位置を定め、その数をカウントします。この例は、基になるプロバイダが類似の機能をサポートしていない場合を想定しています。

// The WFC class includes the ADO objects.
import com.ms.wfc.data.*;
import java.io.* ;
import com.ms.com.*;

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

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

    // FindX function

    static void FindX()
    {

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

        // Declarations.
        BufferedReader in = 
            new BufferedReader (new InputStreamReader(System.in));
        String strCnn = "DSN=Pubs;Provider=MSDASQL;uid=sa;pwd=;";
        Variant varMark = null;
        int intCount = 0;

        try
        {
            cnConn1 = new Connection();
            cnConn1.open(strCnn);
            rstTitles = new Recordset();
            rstTitles.open("SELECT title_id FROM titles",
                    cnConn1,
                    AdoEnums.CursorType.STATIC,
                    AdoEnums.LockType.READONLY,
                    AdoEnums.CommandType.TEXT);

            //  The default parameters are sufficient to search forward
            //  through a Recordset.
            rstTitles.find("title_id LIKE 'BU%'");

            // Skip current record to avoid finding the same row repeatedly.
            // The bookmark is redundant because Find searches from current
            // position.
            while(!rstTitles.getEOF()) // Continue if last find succeeded.
            {
                System.out.println("Title ID: "
                                   + rstTitles.getField("title_id").getString());
                intCount++; // Count the last title found.
                varMark = (Variant)rstTitles.getBookmark(); 
                // Note current position.
                rstTitles.find("title_id LIKE 'BU%'",
                         1,
                         AdoEnums.SearchDirection.FORWARD,
                         varMark);
            }

            // Cleanup objects before exit.
            rstTitles.close();
            cnConn1.close();

            System.out.println("\nThe number of business titles is " +
                               Integer.toString(intCount));
            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 (rstTitles != null)
            {
                PrintProviderError(rstTitles.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");
    }
}