Idea的jdbc中的查询与增删该

在上一篇的折磨中 终于写好了代码

来总结一下其中的奥妙

（相同部分：）1、有mysql并且与主机建立连接 2、有jar包并且复制到自己创建的libs文件下，右键add

3、需要写main方法

4、需要写

Class.forName("com.mysql.jdbc.Driver");

　　来注册驱动

5、都需要

Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mysql", "root", "root");

　　建立与数据库连接（如果报错找不到的话 可以看一下我上一篇踩坑记录，比较踩了一晚上）

（不同部分：）

-增加的语句中写的是返回的行数以及sql语句

Statement的executeUpdate方法；

 String sql = "INSERT INTO db1(age,NAME,TIME) VALUE(28,\"tt\",NULL)";//直接从可视化复制过来比较正确
            Statement stmt = conn.createStatement();
            int i = stmt.executeUpdate(sql);
            System.out.println(i);

-查找的语句是返回查询结果以及写的是sql查询语句，用的是

Statement的executeQuery方法

String sql = "SELECT * FROM db1";//直接从可视化复制过来比较正确
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery(sql);
            System.out.println(rs);

            while (rs.next()){
                int id = rs.getInt("id");
                String name = rs.getString("name");
                int age = rs.getInt("age");
                Time time = rs.getTime("time");
                System.out.println(id+" "+name+" "+age+" "+time);
            }
            rs.close();

　　*完整代码

package cn.it.com;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;

public class JdbcInset {
    public static void main(String[] args) {
        try {
            Class.forName("com.mysql.jdbc.Driver");
            Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mysql", "root", "root");
            String sql = "INSERT INTO db1(age,NAME,TIME) VALUE(28,\"tt\",NULL)";//直接从可视化复制过来比较正确
            Statement stmt = conn.createStatement();
            int i = stmt.executeUpdate(sql);
            System.out.println(i);
        } catch (SQLException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }

    }
}

package cn.it.com;

import java.sql.*;

public class JdbcFind {
    public static void main(String[] args) {
        try {
            Class.forName("com.mysql.jdbc.Driver");
            Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mysql", "root", "root");
            String sql = "SELECT * FROM db1";//直接从可视化复制过来比较正确
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery(sql);
            System.out.println(rs);

            while (rs.next()){
                int id = rs.getInt("id");
                String name = rs.getString("name");
                int age = rs.getInt("age");
                Time time = rs.getTime("time");
                System.out.println(id+" "+name+" "+age+" "+time);
            }
            rs.close();
        } catch (SQLException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }


    }
}