数据库之JDBC入门

1. 数据表:
   

2. 代码实现（注：jar包用的8.0版本）

    import java.sql.*;
    import java.util.Scanner;
   
    public class MyDatabase {
            public static void main(String[] args) {
                    Scanner sc = new Scanner(System.in);
                    System.out.print("请输入查询记录的ID:");
                    int inputid = sc.nextInt();
                    Connection con=null;
            PreparedStatement pst=null;
            ResultSet rs=null;
   
            try {
                //1.导入驱动jar包
                //2.注册数据库驱动
                Class.forName("com.mysql.cj.jdbc.Driver");
                //3.获取数据库连接对象Connection
                con = DriverManager.getConnection("jdbc:mysql://localhost:3306/mytest","root","root");
                //4. 定义sql
                String sql = "select * from student where id=?";
               // 5. 获取执行sql语句的对象 PrepareStatement,并设置参数值
               pst = con.prepareStatement(sql);
                pst.setInt(1,inputid);
               // 6. 执行sql，接受返回结果
                rs = pst.executeQuery();
                //7. 处理结果
                while (rs.next())
                {
                    int id = rs.getInt(1);
                    String name = rs.getString("name");
                    int age = rs.getInt("age");
                    System.out.println("id:"+id+",name:"+name+",age:"+age);
                }
   
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            } catch (SQLException e) {
                e.printStackTrace();
            }finally {
                //8. 释放资源
                //避免空指针异常
                if(rs != null){
                    try {
                        rs.close();
                    } catch (SQLException e) {
                        e.printStackTrace();
                    }
                }
   
                if(pst != null){
                    try {
                        pst.close();
                    } catch (SQLException e) {
                        e.printStackTrace();
                    }
                }
   
                if(con != null){
                    try {
                        con.close();
                    } catch (SQLException e) {
                        e.printStackTrace();
                    }
                }
            }
        }
    }
   

3. 运行结果如图：