基础JDBC连接与使用教程

Jdbc(Java DataBase Connectivity), 是一种JAVA数据库连接方法。

实现步骤

1.加载驱动（先引入mysql的jar包）
2.创建连接
3.编写sql语句
4.获得statement对象（用来接收sql语句）
5.执行sql语句获得结果
6.结果处理
7.关闭资源

具体代码

先创建一个tb_user表(id,username,password)

查询

package com.JDBC;

import java.sql.*;
//数据库查询
public class find {
	public static void main(String[] args) {
		try{
			//加载驱动
			Class.forName("com.mysql.jdbc.Driver");
			//创建连接
			Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/train","root","123456");
			System.out.println("创建连接成功");
			//写sql语句
			String sql="select * from tb_user";
			//获得statement对象
			PreparedStatement statement = connection.prepareStatement(sql);
			//执行sql得到结果
			ResultSet resultSet = statement.executeQuery();
			//处理结果
			while (resultSet.next()){
				System.out.println(resultSet.getInt(1));
				System.out.println(resultSet.getString(2));
				System.out.println(resultSet.getString(3));
			}
			//关闭资源
			DBUtil.closeAll(resultSet,statement,connection);
		}catch (Exception e){
			System.out.println(e);
		}
	}
}

添加

package com.JDBC;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;

public class add {
	public static void main(String[] args) {
		try{
			//加载驱动
			Class.forName("com.mysql.jdbc.Driver");
			//创建连接
			Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/train","root","123456");
			System.out.println("创建连接成功");
			//写sql语句
			String sql="insert tb_user values(null,'whb','785')";
			//获得statement对象
			PreparedStatement statement = connection.prepareStatement(sql);
			//执行sql得到结果
			statement.executeUpdate();
			//处理结果
			//关闭资源
			DBUtil.closeAll(null,statement,connection);
		}catch (Exception e){
			System.out.println(e);
		}

	}
}

删除

package com.JDBC;

import java.sql.*;

public class Delete {
	public static void main(String[] args) {
		try{
			//加载驱动
			Class.forName("com.mysql.jdbc.Driver");
			//创建连接
			Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/train","root","123456");
			System.out.println("创建连接成功");
			//写sql语句
			String sql="delete from tb_user where id = 2";
			//获得statement对象
			PreparedStatement statement = connection.prepareStatement(sql);
			//执行sql得到结果
			statement.executeUpdate();
			//处理结果

			//关闭资源
			DBUtil.closeAll(null,statement,connection);
		}catch (Exception e){
			System.out.println(e);
		}

	}
}

修改

package com.JDBC;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;

public class Change {
	public static void main(String[] args) {
		try{
			//加载驱动
			Class.forName("com.mysql.jdbc.Driver");
			//创建连接
			Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/train","root","123456");
			System.out.println("创建连接成功");
			//写sql语句
			String sql="UPDATE tb_user set password = 423 where id=1";
			//获得statement对象
			PreparedStatement statement = connection.prepareStatement(sql);
			//执行sql得到结果
			statement.executeUpdate();
			//处理结果
			//关闭资源
			DBUtil.closeAll(null,statement,connection);
		}catch (Exception e){
			System.out.println(e);
		}

	}
}

关闭方法

package com.JDBC;

import java.sql.*;

public class DBUtil {
//	public static Connection getConnection() throws ClassNotFoundException, SQLException {
//		//加载驱动
//		Class.forName("com.mysql.jdbc.Driver");
//		//创建连接
//		Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/train","root","123456");
//		System.out.println("创建连接成功");
//		return connection;
//	}
	public static void closeAll(ResultSet resultSet, Statement statement, Connection connection) throws SQLException {
		if (resultSet!=null){
			resultSet.close();
		}
		if (statement!=null){
			statement.close();
		}
		if (connection!=null){
			connection.close();
		}

	}
}

简单易学，谢谢观看！