indexing mutilple tables in solr using DIH - solr

Question

I'm developing search engine using Solr and I've been successful in indexing data from one table using DIH (Dataimport Handler). What I need is to get search result from 5 different tables. I couldn't do this without help.
if we assume x table with x rows, there should be x * x documents from each table, which lead to, 5x documents if I have 5 tables as total. In dataconfig.xml, I created 5 seperate entities in single document as shown below. the result from indexed data when I query *:* is only 6 of the entity users and 3 from entity classes which is the number of users total rows which is 9.
Clearly, this way didn't work for me, so how can I achieve this using only single core?
note: I followed DIHQuickStart and DIH tutorial which didn't help me.
<document>
<!-- Users -->
<entity dataSource="JdbcDataSource" name=" >
<field column="name" name="name" sourceColName="name" />
<field column="username" name="username" sourceColName="username"/>
<field column="email" name="email" sourceColName="email" />
<field column="country" name="country" sourceColName="country" />
</entity>
<!-- Classes -->
<entity dataSource="JdbcDataSource" name="classes" >
<field column="code" name="code" sourceColName="code" />
<field column="title" name="title" sourceColName="title" />
<field column="description" name="description" sourceColName="description" />
</entity>
<!-- Schools -->
<entity dataSource="JdbcDataSource" name="schools" >
<field column="school_name" name="school_name" sourceColName="school_name" />
<field column="country" name="country" sourceColName="country" />
<field column="city" name="city" sourceColName="city" />
</entity>
<!-- Resources -->
<entity dataSource="JdbcDataSource" name="resources" >
<field column="title" name="title" sourceColName="title" />
<field column="description" name="description" sourceColName="description" />
</entity>
<!-- Tasks -->
<entity dataSource="JdbcDataSource" name="tasks" >
<field column="title" name="title" sourceColName="title" />
<field column="description" name="description" sourceColName="description" />
</entity>
</document>

Answer 1

you need to look at the structures of your tables then either create queries with joins or creat nested entities like this for example
<dataConfig>
<dataSource driver="org.hsqldb.jdbcDriver" url="jdbc:hsqldb:/temp/example/ex" user="sa" />
<document name="schools">
<entity name="school" query="select * from schools s ">
<field column="school_name" name="school_Name" />
<entity name="school_class" query="select * from schools_classes sc where sc.school_name = '${school.school_name}'">
<field column="class_code" name="class_code" />
<entity name="class" query="select class_name from classes c where c.class_name= '${school_class.class_code}'">
<field column="class_name" name="class_name" />
</entity>
</entity>
</entity>
</document>
</dataConfig>