目录

JDBC简介

JDBC的使用

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JDBC简介

JDBC(Java DataBase Connectivity)是用Java操作数据库的一套API。

sun公司官方定义的一套操作所有关系型数据库的规范，即接口。各个数据库厂商去实现这套接口，提供数据库驱动jar包。我们可以使用这套接口(JDBC)来编程，真正执行的代码是驱动jar包中的实现类。

JDBC的使用

建表语句如下

create table user(id int unsigned primary key auto_increment comment 'ID',name varchar(100) comment '姓名',age tinyint unsigned comment '年龄',gender tinyint unsigned comment '性别, 1:男, 2:女',phone varchar(11) comment '手机号'
) comment '用户表';
insert into user(id, name, age, gender, phone) VALUES (null,'白眉鹰王',55,'1','18800000000');
insert into user(id, name, age, gender, phone) VALUES (null,'金毛狮王',45,'1','18800000001');
insert into user(id, name, age, gender, phone) VALUES (null,'青翼蝠王',38,'1','18800000002');
insert into user(id, name, age, gender, phone) VALUES (null,'紫衫龙王',42,'2','18800000003');
insert into user(id, name, age, gender, phone) VALUES (null,'光明左使',37,'1','18800000004');
insert into user(id, name, age, gender, phone) VALUES (null,'光明右使',48,'1','18800000005');

User.java内容如下

package com.hi1220.demo.pojo;public class User {private Integer id;private String name;private short age;private short gender;private String phone;public User() {}public User(Integer id, String name, short age, short gender, String phone) {this.id = id;this.name = name;this.age = age;this.gender = gender;this.phone = phone;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public short getAge() {return age;}public void setAge(short age) {this.age = age;}public short getGender() {return gender;}public void setGender(short gender) {this.gender = gender;}public String getPhone() {return phone;}public void setPhone(String phone) {this.phone = phone;}@Overridepublic String toString() {return "User{" +"id=" + id +", name='" + name + '\'' +", age=" + age +", gender=" + gender +", phone='" + phone + '\'' +'}';}
}

 DemoApplicationTests.java内容如下

package com.hi1220.demo;import com.hi1220.demo.pojo.User;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;@SpringBootTest
class DemoApplicationTests {@Testpublic void testJdbc() throws Exception {//1. 注册驱动Class.forName("com.mysql.cj.jdbc.Driver");//2. 获取连接对象String url = "jdbc:mysql://localhost:3306/mybatis";String username = "root";String password = "root";Connection connection = DriverManager.getConnection(url, username, password);//3. 获取执行SQL的对象Statement,执行SQL,返回结果String sql = "select * from user";Statement statement = connection.createStatement();ResultSet resultSet = statement.executeQuery(sql);//4. 封装结果数据List<User> userList = new ArrayList<>();while (resultSet.next()){int id = resultSet.getInt("id");String name = resultSet.getString("name");short age = resultSet.getShort("age");short gender = resultSet.getShort("gender");String phone = resultSet.getString("phone");User user = new User(id,name,age,gender,phone);userList.add(user);}System.out.println(userList);//5. 释放资源statement.close();connection.close();}
}

测试结果如下