Solr-DIH定义&导入多对多字段 [英] Solr - DIH define & import many-to-many field

问题描述

我有两个MySQL表book和author，它们具有many-to-many关系，通过book_author_mapper完成，其行包含列book_id/author_id.

I've two MySQL tables book and author, they have many-to-many relationship, done via book_author_mapper whose row contain columns book_id / author_id.

在Solr中，我有一个查询来获取书单，对于每本书，我需要为该书获取一个author_id数组.

In Solr, I have a query to get book list, for each book I need to get an array of author_id for the book.

当前，我正在考虑使用多值字段来存储图书ID.

Currently, I am thinking about to use a multi-valued field to store book ids.

我的问题是:

• 如何定义字段，以及如何在DIH中编写SQL，看来需要多个SQL，对吗?谢谢.
• 如果我不仅要获取author_id列表，还要获取每个author_id的author_name，是否可以?

• How to define the field, and how to write the SQL in DIH, it seems need multiple SQL, right? Thx.
• If I want to get not just the author_id list, but as well as author_name for each author_id, is that possible?

推荐答案

查看doc&谷歌搜索，我已经解决了这个问题.

After viewing doc & googling, I have kind solved the problem.

• 书
• 作者
• book_author_map(这是多对多关系的中间表)

<?xml version="1.0" encoding="UTF-8" ?>
<dataConfig>
    <dataSource type="JdbcDataSource" driver="com.mysql.jdbc.Driver"
        url="jdbc:mysql://localhost:3306/test?characterEncoding=utf8&amp;zeroDateTimeBehavior=convertToNull" user="root"
        password="123456" />
    <document>
        <entity name="book" pk="id"
            query="SELECT * FROM book where status = 0 limit 200000;"
            deltaImportQuery="SELECT * FROM book where status = 0 and id='${dih.delta.id}' limit 200000;"
            deltaQuery="select id from book where status = 0 and CONVERT_TZ(`update_date`, @@session.time_zone, '+00:00')  &gt; '${dih.last_index_time}'"
        >
            <entity name="author"
                query="SELECT au.cn_name as author_cn_name FROM author AS au JOIN book_author_map AS bam ON au.id = bam.author_id WHERE bam.book_id = ${book.id} limit 10;"
            >
                <field name="authors" column="author_cn_name" />
            </entity>
        </entity>
    </document>
</dataConfig>

字段定义

<field name="cn_name" type="textComplex" indexed="true" stored="true" />
<field name="en_name" type="textComplex" indexed="true" stored="true" />

<field name="status" type="int" indexed="true" stored="true" />

<field name="authors" type="textComplex" indexed="true" stored="true" multiValued="true" />

---

待办事项

• parentDeltaQuery它获取父实体的pk，但是在调用它时，该怎么办?那有必要吗?
• 子实体中的deltaQuery和parentDeltaQuery是否必要?

---

TODOs

• parentDeltaQuery It get pk of parent entity, but when it is called, and what is do? Is that necessary?
• Does deltaQuery and parentDeltaQuery necessary in sub entity?

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