SpringBoot初体验-集成Mybatis

一、引入Maven依赖

<!-- mybatis 依赖包-->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>1.3.2</version>
</dependency>

二、配置Mapper接口路径

• 配置Mapper的位置通常有两种方式
• 1、在主类通过注解配置Mapper的包路径

@SpringBootApplication
@MapperScan("top.haostudy.springbootdemo.mapper")
public class SpringbootDemoApplication {

   public static void main(String[] args) {
      SpringApplication.run(SpringbootDemoApplication.class, args);
   }

}

• 2、直接在mapper上使用@Mapper注解

@Mapper
public interface ArticleEntityMapper {
    ArticleEntity selectByAuthorId(@Param("authorId") int authorId)
}

三、配置application.yml

# 配置Mapper.xml的路径
mybatis:
  mapper-locations: classpath:/mapper/*/*.xml

四、编写mapper接口和mapper.xml文件

• 在resouces下建立mapper文件夹，编写相关mapper.xml

<?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">
<!-- namespace:配置Mapper接口的全路径 -->
<mapper namespace="top.haostudy.springbootdemo.mapper.ArticleEntityMapper">
    <!-- 通用查询映射结果 type:配置返回对象的全路径-->
    <resultMap id="BaseResultMap" type="top.haostudy.haostudyapi.model.dao.ArticleEntity">
        <id column="article_id" property="articleId" />
        <result column="type_id" property="typeId" />
        <result column="content" property="content" />
        <result column="create_time" property="createTime" />
        <result column="update_time" property="updateTime" />
        <result column="author_id" property="authorId" />
        <result column="cover_img" property="coverImg" />
        <result column="article_title" property="articleTitle" />
        <result column="read_count" property="readCount" />
    </resultMap>

    <!-- 通用查询结果列 -->
    <sql id="Base_Column_List">
        article_id, type_id, content, create_time, update_time, author_id, cover_img, article_title, read_count
    </sql>

    <select id="selectByAuthorId" resultMap="BaseResultMap">
        select
        <include refid="Base_Column_List"></include>
        from
        article_entity
        where author_id = #{authorId}
    </select>
</mapper>

五、Maven多模块项目特殊配置

• 1、主启动类上增加注解配置

// 如果是多模块Maven项目，需要指定Spring扫描的包路径，确保其他模块的Bean也能被扫描
@SpringBootApplication(scanBasePackages = "top.haostudy")
// 指定Mapper接口所在的包路径
@MapperScan("top.haostudy.springbootdemo.mapper")
public class SpringbootDemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringbootDemoApplication.class, args);
    }

}

2、配置application.yml

• 如果是多模块Maven项目，这里得配置成classpath*

mybatis:
  mapper-locations: classpath*:/mapper/*/*.xml

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