Java Web技术栈

JDBC

简介

jdbc就是使用java语言操作关系型数据库的一套API

// 1.注册驱动
Class.forName("com.mysql.jdbc.Driver");
// 2.获取连接对象
String url="jdbc:mysql://127.0.0.1:3306/db1?useSSL=false";
String username="root";
String password="1234";
Connection coon = DriverManager.getConnection(url,username,password);
// 3.定义SQL
String sql = "update account set money = 2000 where id = 1";
// 4.获取执行sql的对象
Statement stmt = conn.createStatement();
// 5.执行SQL
int count = stmt.executeUpdate(sql);
// 6.处理结果
System.out.println(count);
// 7.释放资源
stmt.close();
conn.close();

java database connectivity，java数据库连接

快速入门

package com.gritworld.jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

public class JDBCDemo {
    public static void main(String[] args) throws Exception {
        // 1.注册数据库驱动
        Class.forName("com.mysql.jdbc.Driver");
        // 2.获取连接
        String url = "jdbc:mysql://127.0.0.1:3306/practice?useSSL=false";
        String username = "root";
        String password = "root";
        Connection connection = DriverManager.getConnection(url, username, password);
        // 3.定义sql
        String sql = "select * from account;";
        // 4.获取执行sql的对象
        Statement statement = connection.createStatement();
        // 5.执行sql
        ResultSet resultSet = statement.executeQuery(sql);
        // 6.处理结果 以下两种方式都可以
        /*while (resultSet.next()) {
            int id = resultSet.getInt(1);
            String name = resultSet.getString(2);
            Double money = resultSet.getDouble(3);
            System.out.println(id + "=>" + name + "=>" + money);
        }*/

        while (resultSet.next()) {
            int id = resultSet.getInt("id");
            String name = resultSet.getString("name");
            double money = resultSet.getDouble("money");
            System.out.println(id + "=>" + name + "=>" + money);
        }
        statement.close();
        connection.close();
    }
}