动力节点笔记
- import java.sql.*;
- //采用Statement查询全部数据
- public class QueryTest03 {
- public static void main(String[] args) {
- Connection conn = null;
- Statement stmt = null;
- ResultSet rs = null;
- try {
- //第一步,加载数据库驱动,不同的数据库驱动程序不一样
- Class.forName("oracle.jdbc.driver.OracleDriver");
- //第二部,得到数据库连接
- String dburl = "jdbc:oracle:thin:@localhost:1521:orcl";
- //String dburl = "jdbc:oracle:thin:@192.168.21.1:1521:orcl";
- //String dburl = "jdbc:oracle:thin:@127.0.0.1:1521:orcl";
- String userName = "system";
- String password = "wanwan";
- conn = DriverManager.getConnection(dburl, userName, password);
- //System.out.println(conn);
- //第三步,创建Statement,执行SQL语句
- stmt = conn.createStatement();
- //第四部,取得结果集
- rs = stmt.executeQuery("select * from tb_student");
- while (rs.next()) {
- int id = rs.getInt("id");
- String name = rs.getString("name");
- System.out.println(id + " , " + name);
- }
- System.out.println("============================");
- //可以采用索引号取得字段的值,索引从1开始,
- //尽量不要使用索引号的方式,因为不明确
- rs = stmt.executeQuery("select * from tb_student");
- while (rs.next()) {
- int id = rs.getInt(1);
- String name = rs.getString(2);
- System.out.println(id + "," + name);
- }
- } catch (ClassNotFoundException e) {
- e.printStackTrace();
- } catch (SQLException e) {
- e.printStackTrace();
- } finally {
- //注意关闭原则:从里到外
- try {
- if (rs != null) {
- rs.close();
- }
- if (stmt != null) {
- stmt.close();
- }
- if (conn != null) {
- conn.close();
- }
- } catch(SQLException e) {
- }
- }
- }
- }