String forn="com.microsoft.sqlserver.jdbc.sqlServerDriver";//数据库驱动
String url = "jdbc:sqlserver://172_16_0_6:1433;databaseName=mydbname ";连接的url

String forn="com.MysqL.jdbc.Driver";String url = "jdbc:MysqL://localhost:3306/mydbname ";连接的url

import java.sql.*

private Connection ct=null;
private Statement st=null;

 1 private void Db(){
 2         String forn="com.MysqL.jdbc.Driver"; 3         String url = "jdbc:MysqL://localhost:3306/db_library";连接的url
 4         String user="root";  用户名
 5         String password="root";密码
 6         try {
 7             Class.forName(forn);注册、加载特定的驱动程序
 8         } catch (ClassNotFoundException e) { 
 9             JOptionPane.showMessageDialog(null,"加载数据库失败01");
10             System.exit(0);关闭整个应用
11             e.printStackTrace();
12         }
13         14             ct=DriverManager.getConnection(url,user,password);创建连接，创建连接Connection对象
15         }  (sqlException e1) {
16             JOptionPane.showMessageDialog(数据库失败02"+e1.toString());
17             System.exit(0);18             e1.printStackTrace();
19 20         21             st=ct.createStatement();创建会话对象，用Connection对象生成Statement对象
22         }  (sqlException e3) {
23             JOptionPane.showMessageDialog(数据库失败03"24             System.exit(0);25             e3.printStackTrace();
26 27         JOptionPane.showMessageDialog(数据库成功了"28 }

 2     执行sql语句
 3         ResultSet rex = st.executeQuery("select *from tb_books where b_id=1" 4         判断是否查询到值
 5         if(rex.next()){ 
 6             String ss=rex.getString("字段名" 7             JOptionPane.showMessageDialog(ss);    
 8  9 } 10         e1.printStackTrace();
11 }

 2         while(rex.next()){
11 }

1 2         设置更新的sql语句
3         String sql2="update tb_test set text1='123',text2='1234' where id='1'"4         int ii = st.executeUpdate(sql2);返回影响行数
5         JOptionPane.showConfirmDialog(ii);
6 } 7        e1.printStackTrace();
8 }