io Programmo 39/IOPROG_39.ISO/SOFT/sdkjava40.exe/data1.cab/fg_Samples/Samples/JDBC/SimpleSelect.java

Java Source | 2000-05-04 | 4.5 KB | 187 lines

//
//----------------------------------------------------------------------------
//
// This is a sample file that shows how to connect to a ODBC data source.
// Please make sure you have a valid data source URL in your url variable.
// (C) Copyright 1995 - 1999 Microsoft Corporation.  All rights reserved.
//
//----------------------------------------------------------------------------


import java.sql.*;

class SimpleSelect {


public static void main (String args[]) {
    String url   = "JDBC:ODBC:my_dsn";
    String query = "SELECT * FROM authors";

    try {

        // Load the jdbc-odbc bridge driver

        Class.forName ("com.ms.jdbc.odbc.JdbcOdbcDriver");

        DriverManager.setLogStream(System.out);

        // Attempt to connect to a driver.

        Connection con = DriverManager.getConnection (
            url, "my_user", "my_pwd");

        // If we were unable to connect, an exception
        // would have been thrown.  So, if we get here,
        // we are successfully connected to the URL

        // Check for, and display and warnings generated
        // by the connect.

        checkForWarning (con.getWarnings ());

        // Get the DatabaseMetaData object and display
        // some information about the connection

        DatabaseMetaData dma = con.getMetaData ();

        System.out.println("\nConnected to " + dma.getURL());
        System.out.println("Driver       " +
            dma.getDriverName());
        System.out.println("Version      " +
            dma.getDriverVersion());
        System.out.println("");

        // Create a Statement object so we can submit
        // SQL statements to the driver

        Statement stmt = con.createStatement ();

        // Submit a query, creating a ResultSet object

        ResultSet rs = stmt.executeQuery (query);

        // Display all columns and rows from the result set

        dispResultSet (rs);

        // Close the result set

        rs.close();

        // Close the statement

        stmt.close();

        // Close the connection

        con.close();
    }

    catch (SQLException ex) {

        // A SQLException was generated.  Catch it and
        // display the error information.  Note that there
        // could be multiple error objects chained
        // together

    System.out.println ("\n*** SQLException caught ***\n");

    while (ex != null) {
        System.out.println ("SQLState: " +
                ex.getSQLState ());
        System.out.println ("Message:  " + ex.getMessage ());
        System.out.println ("Vendor:   " +
                ex.getErrorCode ());
        ex = ex.getNextException ();
        System.out.println ("");
        }
    }
    catch (java.lang.Exception ex) {

        // Got some other type of exception.  Dump it.

        ex.printStackTrace ();
    }
}

//-------------------------------------------------------------------
// checkForWarning
// Checks for and displays warnings.  Returns true if a warning
// existed
//-------------------------------------------------------------------

private static boolean checkForWarning (SQLWarning warn)
                                        throws SQLException  {
    boolean rc = false;

    // If a SQLWarning object was given, display the
    // warning messages.  Note that there could be
    // multiple warnings chained together

    if (warn != null) {
        System.out.println ("\n *** Warning ***\n");
        rc = true;
        while (warn != null) {
            System.out.println ("SQLState: " +
                warn.getSQLState ());
            System.out.println ("Message:  " +
                warn.getMessage ());
            System.out.println ("Vendor:   " +
                warn.getErrorCode ());
            System.out.println ("");
            warn = warn.getNextWarning ();
        }
    }
    return rc;
}

//-------------------------------------------------------------------
// dispResultSet
// Displays all columns and rows in the given result set
//-------------------------------------------------------------------

private static void dispResultSet (ResultSet rs)
    throws SQLException
{
    int i;

    // Get the ResultSetMetaData.  This will be used for
    // the column headings

    ResultSetMetaData rsmd = rs.getMetaData ();

    // Get the number of columns in the result set

    int numCols = rsmd.getColumnCount ();

    // Display column headings

    for (i=1; i<=numCols; i++) {
        if (i > 1) System.out.print(",");
        System.out.print(rsmd.getColumnLabel(i));
    }
    System.out.println("");

    // Display data, fetching until end of the result set

    boolean more = rs.next ();
    while (more) {

        // Loop through each column, getting the
        // column data and displaying

        for (i=1; i<=numCols; i++) {
            if (i > 1) System.out.print(",");
            System.out.print(rs.getString(i));
        }
        System.out.println("");

        // Fetch the next result set row

        more = rs.next ();
    }
}

}