回顾jdbc

@Autowired
   private ParameterMapper parameterMapper;


    //回顾jdbc占位符拼接
    @Test
    public void fun1() throws Exception {
        String username="张三";
        Class.forName("com.mysql.jdbc.Driver");
        Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/db01?useSSL=false"
                , "root", "hsp");

        PreparedStatement ps = connection.prepareStatement("select * from t_emp where emp_name=?");
        ps.setString(1,username);
        ResultSet resultSet = ps.executeQuery();
        while(resultSet.next()){
            String emp_name = resultSet.getString("emp_name");
            int eid = resultSet.getInt("eid");
            int age = resultSet.getInt("age");
            String sex = resultSet.getString("sex");
            String email = resultSet.getString("email");
            int did = resultSet.getInt("did");
            System.out.println("结果是:"+emp_name+eid+age+sex+email);
        }
    }