For multiple value fields using the DIH, i use group_concat with the
regextransformer's splitby:
ex:
<entity dataSource="grad_schools" query="
SELECT group_concat(professors.name separator '|') as
university_professors
FROM professors
WHERE professors.university_guid = '${universities.guid}'
"
transformer="RegexTransformer">
<field column="university_professors" splitBy="\|" />
</entity>
hope that's helpful.
@tommychheng
Programmer and UC Irvine Graduate Student
Find a great grad school based on research interests: http://gradschoolnow.com
On 8/6/10 4:39 PM, harrysmith wrote:
I'm having a difficult time understanding how multivariable fields work with
the DataImportHandler when the source is a RDBMS. I've read the following
from the wiki:
----------
What is a row?
A row in DataImportHandler is a Map (Map<String, Object>). In the map , the
key is the name of the field and the value can be anything which is a valid
Solr type. The value can also be a Collection of the valid Solr types (this
may get mapped to a multi-valued field). If the DataSource is RDBMS a query
cannot emit a multivalued field. But it is possible to create a multivalued
field by joining an entity with another.i.e if the sub-entity returns
multiple rows for one row from parent entity it can go into a multivalued
field. If the datasource is xml, it is possible to return a multivalued
field.
--------------
How does one 'join an entity with another'? Below are the relevant sections
of my schema.xml and data-config.xml.
schema.xml
<dynamicField name="*_s" type="string" indexed="true" stored="true"
multiValued="true" />
=========
data-config.xml
<entity name="item" query="select * from project_items where
projectid_fk=1">
<field column="ID_PK" name="id" />
<entity name="terms" query="select distinct DESC_TERM from
tem_metadata where item_id=${item.ID_PK}">
<entity name="metadata" query="select * from
term_metadata where item_id=${item.ID_PK} AND
desc_term='${terms.DESC_TERM}'">
<field name="${terms.DESC_TERM}_s"
column="TEXT_VALUE" />
</entity>
</entity>
</entity>
========================
I have multiple terms (rows) in the term_metadata table that are returned
from the query, but only the first one gets added. Am I missing something
obvious?
