[大数据]JDBC之MySQL增删改查数据库

简单的增删改查

package com.company;

import java.sql.*;
import java.util.Date;

public class hello01jdbc {
    //MySQL连接的配置信息
    private static String driver="com.mysql.cj.jdbc.Driver";
    private static String url="jdbc:mysql://localhost:3306/scott?useUnicode=true&characterEncoding=utf8&useSSL=false&serverTimezone=GMT";
    //   url=jdbc:mysql://ip:port/hvk_l?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone =Asia/Shanghai
    private static final String user = "root";
    private static final String password = "123456";
    public static void main(String[] args) throws ClassNotFoundException, SQLException {
    }
    /**
     * 数据库查询语句
     *
     * @throws ClassNotFoundException
     * @throws SQLException
     */
    private static void dql() throws ClassNotFoundException, SQLException {
        //加载驱动
        Class.forName(driver);
        //获取链接
        Connection connection =DriverManager.getConnection(url,user,password);
        //获取发送sql对象
        Statement statement =connection.createStatement();
        //创建sql
        String sql= "select * from emp";
        //执行sql获取结果集
        ResultSet resultSet=statement.executeQuery(sql);
        //打印ResultSet(打印的是对象的hash，一般没什么意义)
        //System.out.println(resultSet);
        //打印数据
        while (resultSet.next()) {
            //获取数据
            int empno = resultSet.getInt("empno");
            String ename=resultSet.getString("ename");
            String job=resultSet.getString("job");
            int mgr = resultSet.getInt("mgr");
            Date hiredate =resultSet.getDate("hiredate");
            int sal = resultSet.getInt("sal");
            double comm =resultSet.getDouble("comm");
            int deptnpo = resultSet.getInt("deptno");
            System.out.println(empno+"\t"+ename+"\t"+job+"\t"+mgr+"\t"+hiredate+"\t"+sal+"\t"+comm+"\t"+deptnpo);
        }
    }
    /**
     *
     * 数据库的增删改查
     * @throws ClassNotFoundException
     * @throws SQLException
     */
    private static void dml() throws ClassNotFoundException, SQLException {
        //加载驱动
        Class.forName(driver);
        // 创建链接
        Connection connection = DriverManager.getConnection(url,user,password);
        // 创建对象可以发送sql语句
        Statement statement = connection.createStatement();
        //写一个sql语句(不要带封号)
        //String sql="delete from emp where empno=8888";
        //String sql="update emp set sal =8888 where empno =7788";
        String sql="insert into dept values(11,'行政部','北京')";
        //执行sql获取结果
        int rows = statement.executeUpdate(sql);
        System.out.println("hello01jdbc.main[Affected rows:"+ rows+"]");
    }
}