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 {
    @Autowired
    private UserMapper userMapper;

    @Test
    public 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;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", age='" + age + '\'' +
                ", gender=" + gender +
                ", phone='" + phone + '\'' +
                '}';
    }
}