jdbc+mysql实现增删改查

JDBC (mysql)数据库查询步骤，实现基本数据功能

开始前的准备事项

（1）去MySQL官网安装下载程序jar包，每个版本对应着不同版本的jar包，下载时看好，下载后在eclipse的工程中创建一个lib文件夹，将jar包复制进去并导入。

（2）确保数据库本地服务器处于开启状态，并创建相应的数据库，表，字段，并写入一些初始数据。
JDBC数据库实现增删改查步骤
（一）注册驱动：Class.forName(“com.mysql.cj.jdbc.Driver”);
（二）获取连接：
1.要连接的数据库的url—>String url = “jdbc:mysql://localhost:3306/school?serverTimezone=GMT”;
2.用户名—>String username = “root”;
3.密码 —>String password = “admin”;
（三）创建Connection连接对象 —> Connection connection = DriverManager.getConnection(url,username,password);
（三）创建statement对象—> Statement statement = connection.createStatement();
（四）执行sql语句—> String sql =“select * from student”;
（五）关闭资源—> connection.close();
statement.close();
代码中出现的异常，全部thorws抛出，不进行try捕获

源代码

package com.jdbctest01;

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

import org.omg.CORBA.PUBLIC_MEMBER;

public class JdbcMysqlTest {
	String username = "root";
	String password = "admin";
	Connection connection;
	Statement statement;
	String url = "jdbc:mysql://localhost:3306/school?serverTimezone=GMT";
	
	
	public static void main(String[] args) throws ClassNotFoundException, SQLException {
		// TODO Auto-generated method stub
		JdbcMysqlTest jdbcMysqlTest = new JdbcMysqlTest();
		
		//1、清空表中所有数据
		jdbcMysqlTest.deleteAllData();
		
		//2、增加数据
		jdbcMysqlTest.insertData("李晓帅", "2020001", "山东", "20");
		jdbcMysqlTest.insertData("张一", "20210001", "烟台蓬莱", "19");
		jdbcMysqlTest.insertData("张二", "20210002", "烟台蓬莱", "20");
		jdbcMysqlTest.insertData("张三", "20210003", "烟台蓬莱", "21");
		jdbcMysqlTest.insertData("张四", "20210004", "烟台蓬莱", "22");
		
		//3、查询数据：显示所有记录
		jdbcMysqlTest.selectAllData();
		
		//4、修改数据：根据学号 20210004 修改年龄为18
		jdbcMysqlTest.updateData("20210004","18");
		
		//5、查询数据：显示所有记录
		jdbcMysqlTest.selectAllData();
		
		//6、删除数据：根据学号 20210003 删除记录
		jdbcMysqlTest.deleteData("20210003");
		
		//查询数据：显示所有记录
		jdbcMysqlTest.selectAllData();
	}
	
	//全部删除语句模块
	public int  deleteAllData() throws SQLException, ClassNotFoundException{
		int i = 0;
		Class.forName("com.mysql.cj.jdbc.Driver");
		String sql ="delete from student";
		connection = DriverManager.getConnection(url,username,password);
		statement = connection.createStatement();
		i = statement.executeUpdate(sql);
		if (i==1) {
			System.out.println("删除数据成功");
		}else {
			System.out.println("删除数据失败");
		}
		connection.close();
		statement.close();
		return i;
	}
	
	//插入语句模块
	public int  insertData(String name,String sno,String addr,String age ) throws ClassNotFoundException, SQLException {
		Class.forName("com.mysql.cj.jdbc.Driver");
		String sql ="insert into student values('"+name+"','"+sno+"','"+addr+"','"+age+"')";
		connection = DriverManager.getConnection(url,username,password);
		statement = connection.createStatement();
		int i = statement.executeUpdate(sql);
		if (i==1) {
			System.out.println("插入数据成功");
		}else {
			System.out.println("插入数据失败");
		}
		connection.close();
		statement.close();
		return i;	
	}
	
	//查询语句模块
	public ResultSet  selectAllData() throws ClassNotFoundException, SQLException{
		Class.forName("com.mysql.cj.jdbc.Driver");
		String sql ="select * from student";
		connection = DriverManager.getConnection(url,username,password);
		statement = connection.createStatement();
		ResultSet resultSet = statement.executeQuery(sql);
		while (resultSet.next()) {
			String name = resultSet.getString("name");
			String sno = resultSet.getString("sno");
			String addr = resultSet.getString("addr");
			String age = resultSet.getString("age");
			System.out.println("姓名:"+name);
			System.out.println("学号:"+sno);
			System.out.println("住址:"+addr);
			System.out.println("年龄:"+age);
			System.out.println("----------------------------------------------------");
		}
			System.out.println("全部信息已显示完毕");
			return null;
	}
	
	//更新语句模块
	public int updateData(String sno,String age ) throws ClassNotFoundException, SQLException{
		Class.forName("com.mysql.cj.jdbc.Driver");
		String sql ="update student set age="+age+" where sno='"+sno+"'";
		connection = DriverManager.getConnection(url,username,password);
		statement = connection.createStatement();
		int i = 0 ;
		i = statement.executeUpdate(sql);
		if (i>=1) {
			System.out.println("修改数据成功");
		}else {
			System.out.println("修改数据失败");
		}
		connection.close();
		statement.close();
		return i;	
	}
	
	//删除语句模块
	public int  deleteData(String sno) throws SQLException, ClassNotFoundException{
		int i = 0;
		Class.forName("com.mysql.cj.jdbc.Driver");
		String sql ="delete from student where sno='"+sno+"'";
		connection = DriverManager.getConnection(url,username,password);
		statement = connection.createStatement();
		i = statement.executeUpdate(sql);
		if (i==1) {
			System.out.println("删除指定学号的学生信息成功");
		}else {
			System.out.println("删除指定学号的学生信息失败");
		}
		connection.close();
		statement.close();
		return i;
	}
}