JDBC

  • 数据库驱动

    • 我们的程序会通过数据库驱动和数据库打交道

  • JDBC

    • Sun公司简化开发人员的操作，提供的规范

  • 第一个JDBC项目

    • 创建一个Java项目

    • 导入jar包

    • 编写测试代码

      • 1 create database `jdbcStudy` character set utf8mb4 collate utf8mb4_bin;
2 
3 use `jdbcStudy`;
4 
5 
6 insert into `users`(`id`,`NAME`,`PASSWORD`,`email`,`birthday`)
7 values(1,'zhangsan','123456','zs@sina.com','1980-12-04'),
8 (2,'lisi','123456','lisi@sina.com','1981-12-04'),`jdbcstudy`
9 (3,'wangwu','123456','wangwu@sina.com','1979-12-04');

        建表添加数据

    •  1 public static void main(String[] args) {
 2         //加载驱动
 3         try {
 4             Class.forName("com.mysql.cj.jdbc.Driver");
 5         } catch (ClassNotFoundException e) {
 6             e.printStackTrace();
 7         }
 8         //用户信息和url
 9         String url = "jdbc:mysql://localhost:3306/jdbcstudy?useUnicod=true&characterEncoding=utf8";
10         String userName = "root";
11         String password = "123456";
12 
13         //连接成功，数据库对象
14         try {
15             Connection connection = DriverManager.getConnection(url, userName, password);
16 
17             //执行SQL的对象
18             Statement statement = connection.createStatement();
19 
20             //执行SQL的对象执行SQL
21             String sql = "select * from users";
22 
23             ResultSet resultSet = statement.executeQuery(sql);
24 
25             while (resultSet.next()){
26                 System.out.print("id="+resultSet.getObject("id"));
27                 System.out.print("\tname="+resultSet.getObject("name"));
28                 System.out.print("\tpassword="+resultSet.getObject("password"));
29                 System.out.print("\temail="+resultSet.getObject("email"));
30                 System.out.println("\tbirth="+resultSet.getObject("birthday"));
31             }
32 
33             //释放连接
34             resultSet.close();;
35             statement.close();
36             connection.close();
37 
38         } catch (SQLException e) {
39             e.printStackTrace();
40         }
41 
42     }

      MySQL入门学习day3随笔3_添加数据

      MySQL入门学习day3随笔3_加载_02

  • SQL注入

    • SQL存在漏洞，会被攻击导致数据泄露

  • PreparedStatement

    • Connection connection = null;
PreparedStatement pstm = null;
    try {
        connection = JdbcUtils.getConnection();
        //区别
        //使用问好占位符代替参数
        String sql = "insert into users(id,`NAME`) values(?,?)";
        pstm = connection.prepareStatement(sql);//预编译sql，先写sql然后不执行
        //手动赋值
        pstm.setInt(1, 8);
        pstm.setString(2, "SANJIN");

        //执行
        int i = pstm.executeUpdate();
        if (i > 0) {
             System.out.println("插入成功");
        }
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        try {
            JdbcUtils.release(connection, pstm, null);
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }
    }