MyBatis Memo

[ywlcn]

参考 https://qiita.com/5zm/items/e1faac61a1d00998fb1f

MyBatis实现的全过程

服务器是如何知道需要载入哪些Mapper

• 使用mybatis-spring的机能，需要使用@MapperScan标注，指定扫描的Package对象。

  @MapperScan("com.example.*")  
  public class SpringbootMainApplication {   
  public static void main(String[] args) {  
    SpringApplication.run(SpringbootMainApplication .class, args);   
  }
  }

• 使用mybatis-spring-boot-starter，Spring Boot程序会自动扫描，主程序包里面所有带有@org.apache.ibatis.annotations.Mapper标注的接口。(mybatis 3.4追加的）

  <dependency>
  <groupId>org.mybatis.spring.boot</groupId>
  <artifactId>mybatis-spring-boot-starter</artifactId>
  <version>2.1.0</version>
  </dependency>

Mapper的使用方式

• 直接写在Java文件中

  
  package com.example.mybatistrainmapper.mapper;

import org.apache.ibatis.annotations.Insert; import org.apache.ibatis.annotations.Mapper; import org.apache.ibatis.annotations.Options; import org.apache.ibatis.annotations.Select; import com.example.mybatistrainmapper.domain.Book;

@Mapper public interface BookMapper {

@Insert("INSERT INTO Book (title, details, finished) VALUES (#{title}, #{details}, #{finished})")
@Options(useGeneratedKeys = true, keyProperty = "id")
void insert(Book todo);

@Select("SELECT id, title, details, finished FROM Book WHERE id = #{id}")
Book select(int id);

}

- 配置在XML文件中

@Mapper public interface TodoMapper { void insert(Todo todo); Todo select(int id); }

<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

INSERT INTO Book (title, details, finished) VALUES (#{title}, #{details}, #{finished}) SELECT id, title, details, finished FROM Book WHERE id = #{id}

从接口  如何找到 XML  是通过谁实现的？？？