solr中一对多，多对多关系
先看下官方文档的例子：
假设有如下表结构：
data-config.xml:一对多，多对多的关系写法如下：
-
-
"org.hsqldb.jdbcDriver" url=
"jdbc:hsqldb:/temp/example/ex" user=
"sa" />
-
"products">
-
"item" query=
"select * from item">
-
"ID" name=
"id" />
-
"NAME" name=
"name" />
-
"MANU" name=
"manu" />
-
"WEIGHT" name=
"weight" />
-
"PRICE" name=
"price" />
-
"POPULARITY" name=
"popularity" />
-
"INSTOCK" name=
"inStock" />
-
"INCLUDES" name=
"includes" />
-
-
"feature" query=
"select description from feature where item_id='${item.ID}'">
-
"features" column=
"description" />
-
-
"item_category" query=
"select CATEGORY_ID from item_category where item_id='${item.ID}'">
-
"category" query=
"select description from category where id = '${item_category.CATEGORY_ID}'">
-
"description" name=
"description" />
-
-
-
-
-
一对多写法：
-
"feature" query=
"select description from feature where item_id='${item.id}'">
-
"feature" column=
"description" />
-
多对多写法：
-
"item_category" query=
"select category_id from item_category where item_id='${item.id}'">
-
"category" query=
"select description from category where id = '${item_category.category_id}'">
-
"description" name=
"description" />
-
-
本人使用的是以上的写法，api中也给出了另一种写法，但自己没有测试过：
-
-
"org.hsqldb.jdbcDriver" url=
"jdbc:hsqldb:/temp/example/ex" user=
"sa" />
-
-
"item" query=
"select * from item">
-
"feature" query=
"select description as features from feature where item_id='${item.ID}'"/>
-
"item_category" query=
"select CATEGORY_ID from item_category where item_id='${item.ID}'">
-
"category" query=
"select description as cat from category where id = '${item_category.CATEGORY_ID}'"/>
-
-
-
-
---------------------------------------------------------------------------------------------------------------------------------------------------------------------
刚开始配置完成后，得出的结果始终是一对一：
如上图：假如：item表和item_category表是一对多，但我这边始终得出的结果是一对一，如：name和description不是一个name对应多个description（实际数据库的结果是一对多的）有点不解；
其实，除了data-config.xml文件需要配置外，还有个重要的文件，managed-schema文件（本人使用的是solr7，老版本里是schema.xml，操作都一样，只要名称不同）也需要修改：
添加索引字段：
-
"id" type=
"string" indexed=
"true" stored=
"true" />
-
"name" type=
"string" indexed=
"true" stored=
"true" />
-
"manu" type=
"string" indexed=
"true" stored=
"true" />
-
"weight" type=
"string" indexed=
"true" stored=
"true" />
-
"price" type=
"string" indexed=
"true" stored=
"true" />
-
"popularity" type=
"string" indexed=
"true" stored=
"true" />
-
"inStock" type=
"string" indexed=
"true" stored=
"true" />
-
"includes" type=
"string" indexed=
"true" stored=
"true" />
-
-
"features" type=
"string" indexed=
"true" stored=
"true" />
-
"cat" type=
"string" indexed=
"true" stored=
"true" />
这个是最开始的配置，达不到理想的结果：
由于本人刚学习solr，不太熟悉，网上百度了一翻，才发现还有个：multiValued（多值的）属性，想要的是一个name对应多个description，那么就应该把description配置成多值的，所以添加multiValued属性，修改managed-schema文件：
-
"id" type=
"string" indexed=
"true" stored=
"true" />
-
"name" type=
"string" indexed=
"true" stored=
"true" />
-
"manu" type=
"string" indexed=
"true" stored=
"true" />
-
"weight" type=
"string" indexed=
"true" stored=
"true" />
-
"price" type=
"string" indexed=
"true" stored=
"true" />
-
"popularity" type=
"string" indexed=
"true" stored=
"true" />
-
"inStock" type=
"string" indexed=
"true" stored=
"true" />
-
"includes" type=
"string" indexed=
"true" stored=
"true" />
-
-
"features" type=
"string" indexed=
"true" stored=
"true" multiValued=
"true"/>
-
"cat" type=
"string" indexed=
"true" stored=
"true" multiValued=
"true"/>
再次导入数据，得到想要的结果了
到此完成：
但是在使用中又遇到了一个问题，比如solr查询记录有5条，使用Java查询:
-
HttpSolrClient solrServer = createSolrServer(
"goods");
-
SolrQuery query =
new SolrQuery();
-
query.set(
"q",
"*:*");
-
// 设置分页参数
-
query.setStart(
1);
-
// 每一页多少值
-
query.setRows(
10);
-
QueryResponse response = solrServer.query(query);
-
SolrDocumentList solrDocumentList = response.getResults();
每页10条，从第一页开始，一切看着没问题，可是结果只有4条，solr查询少了一条记录，百思不得其解...
原来数据库默认分页limit（mysql）是1，但solr是0，所以需要把query.setStart(1)--修改为-->query.setStart(0)，从第一页开始，才是正确的！！！
solr继续学习中....