mybatis的简单概括

古城微笑少年丶 2022-03-15 05:20 256阅读 0赞

前文：

mybatis封装大量JDBC连接配置，使程序员更加注重sql语句的编写。其核心为参数的输入和结果集的返回。

零、基本工作流程

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjY4NzA3NA_size_16_color_FFFFFF_t_70][]

一、全局配置文件

spring\_mybatis。xml

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjY4NzA3NA_size_16_color_FFFFFF_t_70 1][]

二、子清单映射文件

mapper/user.xml

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjY4NzA3NA_size_16_color_FFFFFF_t_70 2][]

三、原生myabtis的API的使用

在实现类（service层）中需要使用到sqlSession及其携带的方法。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjY4NzA3NA_size_16_color_FFFFFF_t_70 3][]

四、使用mapper代理的mybatis

使用dao接口，封装了sqlSession，直接调用dao接口即可

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjY4NzA3NA_size_16_color_FFFFFF_t_70 4][]

使用mapper层的前后对比

原生mybatis的API：
    
    //实现类(service层)中：
    sqlSession=MybatisUtil.getSqlSession();
    
    user=(User)sqlSession.selectOne(
    //对应子清单映射文件的完全限定名
    "com.xx.yy.findUserById", id);

使用mapper层的mybatis
    
    //实现类(service层)中：
    User user = userMapper.findUserById(1);//查询id为1的user
    
    //userMapper.java类中：
    User findUserById(Integer id);

五、mybatis通用持久层

1.持久层对比

![20190406162909223.png][]

2.ssm中的通用持久层

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjY4NzA3NA_size_16_color_FFFFFF_t_70 5][]

3.在springboot中的通用持久层

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjY4NzA3NA_size_16_color_FFFFFF_t_70 6][]

pom.xml中配置

<dependency>
    	<groupId>tk.mybatis</groupId>
    	<artifactId>mapper-spring-boot-starter</artifactId>
    	<version>1.1.4</version>
    </dependency>
    <dependency>
    	<groupId>com.github.abel533</groupId>
    	<artifactId>mapper</artifactId>
    	<version>2.3.2</version>
    </dependency>

mybatis官方中文配置：[http://www.mybatis.org/mybatis-3/zh/configuration.html][http_www.mybatis.org_mybatis-3_zh_configuration.html]

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[20190406162909223.png]: /images/20220315/53144518a1d347338edfefe350f7ceba.png
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[http_www.mybatis.org_mybatis-3_zh_configuration.html]: http://www.mybatis.org/mybatis-3/zh/configuration.html