spring-boot-realworld-example-app/src/main/resources/mapper/ArticleMapper.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" >
<mapper namespace="io.spring.infrastructure.mybatis.mapper.ArticleMapper">
    <insert id="insert">
        insert into articles(id, slug, title, description, body, user_id, created_at, updated_at)
        values(
          #{article.id},
          #{article.slug},
          #{article.title},
          #{article.description},
          #{article.body},
          #{article.userId},
          #{article.createdAt},
          #{article.updatedAt})
    </insert>
    <insert id="insertTag">
        insert into tags (id, name) values (#{tag.id}, #{tag.name})
    </insert>
    <insert id="insertArticleTagRelation">
        insert into article_tags (article_id, tag_id) values(#{articleId}, #{tagId})
    </insert>
    <update id="update">
        update articles
          <set>
              <if test="article.title != ''">title = #{article.title},</if>
              <if test="article.title != ''">slug = #{article.slug},</if>
              <if test="article.description != ''">description = #{article.description},</if>
              <if test="article.body != ''">body = #{article.body}</if>
          </set>
        where id = #{article.id}
    </update>
    <delete id="delete">
        delete from articles where id = #{id}
    </delete>
    <sql id="selectArticle">
        select
        A.id articleId,
        A.slug articleSlug,
        A.title articleTitle,
        A.description articleDescription,
        A.body articleBody,
        A.user_id articleUserId,
        A.created_at articleCreatedAt,
        A.updated_at articleUpdatedAt,
        T.id tagId,
        T.name tagName
        from articles A
        left join article_tags AT on A.id = AT.article_id
        left join tags T on T.id = AT.tag_id
    </sql>

    <select id="findById" resultMap="article">
        <include refid="selectArticle"/>
        where A.id = #{id}
    </select>

    <select id="findTag" resultType="io.spring.core.article.Tag">
        select id, name from tags where name = #{tagName}
    </select>

    <select id="findBySlug" resultMap="article">
        <include refid="selectArticle"/>
        where A.slug = #{slug}
    </select>

    <resultMap id="article" type="io.spring.core.article.Article">
        <id column="articleId" property="id"/>
        <result column="articleUserId" property="userId"/>
        <result column="articleTitle" property="title"/>
        <result column="articleSlug" property="slug"/>
        <result column="articleDescription" property="description"/>
        <result column="articleBody" property="body"/>
        <result column="articleCreatedAt" property="createdAt"/>
        <result column="articleUpdatedAt" property="updatedAt"/>
        <collection property="tags" ofType="arraylist" resultMap="tag"/>
    </resultMap>

    <resultMap id="tag" type="io.spring.core.article.Tag">
        <id column="tagId" property="id"/>
        <result column="tagName" property="name"/>
    </resultMap>
</mapper>