当前位置导航:炫浪网>>网络学院>>编程开发>>JAVA教程>>J2EE

JDBC 程序实例


   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();
  }
  }
  }
  
相关内容
赞助商链接