MyBatis一对多查询配置详解：解决常见关联查询问题

<resultMap id="blogResultMap" type="Blog">
    <id property="id" column="id"/>
    <result property="title" column="title"/>
    <result property="content" column="content"/>
    <collection property="comments" ofType="Comment">
        <id property="id" column="id"/>
        <result property="content" column="content"/>
    </collection>
</resultMap>

<resultMap id="blogResultMap" type="Blog">
    <id property="id" column="id"/>
    <result property="title" column="title"/>
    <result property="content" column="content"/>
    <select property="comments" resultMap="commentResultMap">
        SELECT * FROM comments WHERE blog_id = #{id}
    </select>
</resultMap>

<settings>
    <setting name="lazyLoadingEnabled" value="true"/>
</settings>

<collection property="comments" ofType="Comment" fetchType="lazy">
    <id property="id" column="id"/>
    <result property="content" column="content"/>
</collection>

public interface BlogMapper {
    
    Blog selectBlogWithComments(int id);
    
}

<select id="selectBlogWithComments" resultMap="blogResultMap">
    SELECT * FROM blogs WHERE id = #{id}
</select>

public class Blog {
    
    private int id;
    private String title;
    private String content;
    private List<Comment> comments;
    
    // 省略getter和setter方法
}

public class Comment {
    
    private int id;
    private String content;
    
    // 省略getter和setter方法
}