spring-boot-mybatis

1. 功能

连接数据库，进行增删改查操作

2. 类结构图

3. 实现

#实体UserEntity

package com.jihite.entity;

import com.jihite.enums.SexEnum;

public class UserEntity {
    private Long id;
    private String name;
    private String passwd;
    private SexEnum sex;

    public UserEntity() {

    }

    public UserEntity(String name, String passwd, SexEnum sex) {
        this.id = id;
        this.name = name;
        this.passwd = passwd;
        this.sex = sex;
    }

    public long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPasswd() {
        return passwd;
    }

    public void setPasswd(String passwd) {
        this.passwd = passwd;
    }

    public SexEnum getSex() {
        return sex;
    }

    public void setSex(SexEnum sex) {
        this.sex = sex;
    }

    @Override
    public String toString() {
        return String.format("+++++ id:%s, name:%s, passwd:%s, sex:%s\n", id, name, passwd, sex);
    }
}

#枚举 SexEnum

package com.jihite.enums;

public enum SexEnum {
    MAN, WOMAN
}

#接口UserMapper

package com.jihite.mapper;

import com.jihite.entity.UserEntity;
import com.jihite.enums.SexEnum;
import org.apache.ibatis.annotations.*;
import org.springframework.stereotype.Component;

import java.util.List;

@Component
public interface UserMapper {
    @Select("select * from users")
    @Results({
            @Result(property = "name", column = "userName"),
            @Result(property = "passwd", column = "passWord"),
            @Result(property = "sex", column = "user_sex", javaType = SexEnum.class),
    })
    List<UserEntity> getAll();

    @Select("SELECT * FROM users WHERE id=#{id}")
    @Results({
            @Result(property = "name", column = "userName"),
            @Result(property = "passwd", column = "passWord"),
            @Result(property = "sex", column = "user_sex", javaType = SexEnum.class),
    })
    UserEntity getOne(Long id);

    @Insert("INSERT INTO users(userName, passWord, user_sex) VALUES(#{name}, #{passwd}, #{sex})")
    void insert(UserEntity user);

    @Update("UPDATE users SET userName=#{name}, passWord=#{passwd} where id=#{id}")
    void update(UserEntity user);

    @Delete("DELETE from users where id=#{id}")
    void delete(Long id);
}

#Application

package com.jihite;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan("com.jihite.mapper")
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

#datasource

mybatis.type-aliases-package=com.jihite

spring.datasource.driverClassName = com.mysql.jdbc.Driver
spring.datasource.url = jdbc:mysql://ip:port/dbname?useUnicode=true&characterEncoding=utf-8
spring.datasource.username = username
spring.datasource.password = passwd

4. 注释

4.1 加载datasource

springboot会自动加载spring.datasource.*相关配置，数据源就会自动注入到sqlSessionFactory中，sqlSessionFactory会自动注入到Mapper中

我们一切都不用管，直接拿起来使用就行 

4.2 对mapper包进行扫描

方法一：在启动类中添加对mapper包扫描@MapperScan

方法二：直接在Mapper类（UserMapper）上面添加注解@Mapper

建议使用方法一，不然每个mapper加个注解也挺麻烦的

 

4.3 @Result

@Result(property = "name", column = "userName")

写明了实体字段名（name）和数据库字段（userName）的对应关系

5. 代码

链接