Example JDBC Programs

ii

Example JDBC Programs

B.1     Using SELECT import java.net.URL;
import java.sql.*;
class Select {
   public static void main(String argv[]) {
   try {
    // Create a URL specifying an ODBC data source name.
    String url = "jdbc:odbc:wombat";
    // Connect to the database at that URL.
    Connection con = DriverManager.getConnection(url, "kgh", "");
    // Execute a SELECT statement
    Statement stmt = con.createStatement();
    ResultSet rs = stmt.executeQuery("SELECT a, b, c, d, key FROM Table1");
    // Step through the result rows.
    System.out.println("Got results:");
    while (rs.next()) {
     // get the values from the current row:
         int a = rs.getInt(1);
     BigDecimal b = rs.getBigDecimal(2);
     char c[] = rs.getString(3).tocharArray();
     boolean d = rs.getBoolean(4);
     String key = rs.getString(5);
     // Now print out the results:
     System.out.print("  key=" + key);
     System.out.print("  a=" + a);
     System.out.print("  b=" + b);
     System.out.print("  c=");
     for (int i = 0; i < c.length; i++) {
      System.out.print(c[i]);
     }
     System.out.print("  d=" + d);
     System.out.print("\n");
    }
    stmt.close();
    con.close();
   } catch (java.lang.Exception ex) {
    ex.printStackTrace();
   }
   }
}


B.2     Using UPDATE // Update a couple of rows in a database.
import java.net.URL;
import java.sql.*;
class Update {
  public static void main(String argv[]) {
   try {
    // Create a URL specifying an ODBC data source name.
    String url = "jdbc:odbc:wombat";
    // Connect to the database at that URL.
    Connection con = DriverManager.getConnection(url, "kgh", "");
    // Create a prepared statement to update the "a" field of a
    // row in the "Table1" table.
    // The prepared statement takes two parameters.
    PreparedStatement stmt = con.prepareStatement(
       "UPDATE Table1 SET a = ? WHERE key = ?");
    // First use the prepared statement to update
    // the "count" row to 34.
    stmt.setInt(1, 34);
    stmt.setString(2, "count");
    stmt.executeUpdate();
    System.out.println("Updated \"count\" row OK.");
    // Now use the same prepared statement to update the
    // "mirror" field.
    // We rebind parameter 2, but reuse the other parameter.
    stmt.setString(2, "mirror");
    stmt.executeUpdate();
    System.out.println("Updated \"mirror\" row OK.");
    stmt.close();
    con.close();
   } catch (java.lang.Exception ex) {
    ex.printStackTrace();
   }
  }
}


  jdbc@wombat.eng.sun.com or jdbc-odbc@wombat.eng.sun.com
  Copyright ? 1996, 1997 Sun Microsystems, Inc. All rights reserved.