Day06-Mybatis

1. Mybatis介绍

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2. Mybatis连接数据库并返回数据事例

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连接oracle数据的设置方式

spring.application.name=springboot-mybatis
spring.datasource.driver-class-name=oracle.jdbc.OracleDriver
spring.datasource.url=jdbc:oracle:thin:@192.168.100.66:1521:orcl
spring.datasource.username=hr
spring.datasource.password=hr

使用注解方式访问数据库

package com.jingwei.mapper;import com.jingwei.pojo.User;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;import java.util.List;@Mapper//在运行时，会自动生成该接口的实现类对象（代理对象），将对象交给IOC容器
public interface UserMapper {@Select("SELECT * FROM users")List<User> list();
}

使用ioc容器得到userMapper对象，做单元测试

package com.jingwei;import com.jingwei.mapper.UserMapper;
import com.jingwei.pojo.User;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;import java.util.List;@SpringBootTest
class SpringbootMybatisApplicationTests {@Autowiredprivate UserMapper userMapper;@Testpublic void testUser(){List<User> all = userMapper.list();all.forEach(System.out::println);System.out.println(all.size());}}

实体类Bean

package com.jingwei.pojo;
public class User {private Integer id;private String name;private Integer age;private Integer gender;private String phone;public User(Integer id, String name, Integer age, Integer gender, String phone) {this.id = id;this.name = name;this.age = age;this.gender = gender;this.phone = phone;}public User() {}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 Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}public Integer getGender() {return gender;}public void setGender(Integer 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 + '\'' +'}';}
}