Examples

The following are examples of what you can do using the tool (more content to be added here)

1. Allow arbitrary queries as logical views, using the rr:sqlQuery construct:

   <#dc-creator-view>
   rr:sqlQuery """
   SELECT i.item_id AS item_id, mv.text_value AS text_value
   FROM item AS i
   INNER JOIN metadatavalue AS mv
   ON i.item_id=mv.item_id
   INNER JOIN metadatafieldregistry AS mfr
   ON mfr.metadata_field_id=mv.metadata_field_id
   INNER JOIN metadataschemaregistry AS msr
   ON msr.metadata_schema_id=mfr.metadata_schema_id
   WHERE i.in_archive=TRUE AND
   mv.text_value IS NOT NULL AND
   msr.namespace='http://dublincore.org/documents/dcmi-terms/' AND
   mfr.element='creator'
   """.
   

2. Allow functions in the SQL queries, for instance string manipulation functions (such as replace), which can be nested:

   <#dc-language-view>
   rr:sqlQuery """
   SELECT h.handle AS handle,
   replace(replace(replace(replace(replace(replace(mv.text_value,'Greek','ell'),'Spanish','spa'),'German','deu'),'Italian','ita'),'English','eng'),'French','fra') AS text_value
   FROM handle AS h, item AS i, metadatavalue AS mv, metadataschemaregistry AS msr, metadatafieldregistry AS mfr WHERE
   i.in_archive=TRUE AND
   h.resource_id=i.item_id AND
   h.resource_type_id=2 AND
   msr.metadata_schema_id=mfr.metadata_schema_id AND
   mfr.metadata_field_id=mv.metadata_field_id AND
   mv.text_value is not null AND
   i.item_id=mv.item_id AND
   msr.namespace='http://dublincore.org/documents/dcmi-terms/' AND
   mfr.element='language' AND
   mfr.qualifier IS NULL
   """.