在MyBatis中進行多對多關聯查詢可以通過使用<collection>和<association>標簽來實現。

假設有兩個實體類Author和Book，它們之間是多對多的關系，一個作者可以寫多本書，一本書也可以由多個作者共同寫作。首先需要在Author和Book的Mapper文件中配置關聯查詢的SQL語句：

<!-- AuthorMapper.xml -->
<select id="getAuthorById" resultType="Author" parameterType="int">
    SELECT * FROM author WHERE id = #{id}
</select>

<select id="getBooksByAuthorId" resultType="Book" parameterType="int">
    SELECT b.* FROM book b
    JOIN author_book ab ON b.id = ab.book_id
    WHERE ab.author_id = #{authorId}
</select>

<!-- BookMapper.xml -->
<select id="getBookById" resultType="Book" parameterType="int">
    SELECT * FROM book WHERE id = #{id}
</select>

<select id="getAuthorsByBookId" resultType="Author" parameterType="int">
    SELECT a.* FROM author a
    JOIN author_book ab ON a.id = ab.author_id
    WHERE ab.book_id = #{bookId}
</select>

然后在Author和Book實體類中定義關聯的屬性：

public class Author {
    private Integer id;
    private String name;
    private List<Book> books;
    
    // 省略getter和setter方法
}

public class Book {
    private Integer id;
    private String title;
    private List<Author> authors;
    
    // 省略getter和setter方法
}

最后在MyBatis配置文件中配置關聯查詢的映射：

<!-- AuthorMapper.xml -->
<resultMap id="AuthorResultMap" type="Author">
    <id property="id" column="id" />
    <result property="name" column="name" />
    <collection property="books" ofType="Book" resultMap="BookResultMap" />
</resultMap>

<!-- BookMapper.xml -->
<resultMap id="BookResultMap" type="Book">
    <id property="id" column="id" />
    <result property="title" column="title" />
    <collection property="authors" ofType="Author" resultMap="AuthorResultMap" />
</resultMap>

通過以上配置，就可以在AuthorMapper和BookMapper中查詢到多對多關聯的數據，并且在返回結果中包含關聯的實體對象列表。