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The typical operation is to look up a certain metadata value for a DSpace object with a given ID (DSpace 6+ uses a UUID in DSpace 5+the dspace_object_id column, DSpace 5 uses an integer in the resource_id column). First, we find the metadata field in the metadata registry. Say, we're looking for the metadata value (the list of authors) of an item (resource_type_id = 2) with a given UUID ID (dspace_object_id='f2cf9909-0357-4037-8305-4a426bf9a826') where the metadata field is "dc.contributor.author". First, we look up the ID of the "dc" schema in the metadataschemaregistry table (example code for DSpace 6+):

SELECT metadata_schema_id
FROM metadataschemaregistry
WHERE short_id = 'dc';

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SELECT metadata_field_id
FROM metadatafieldregistry
WHERE metadata_schema_id = 1
AND element = 'contributor'
AND qualifier = 'author';

This gives us the metadatathe metadata_field_id value of "9". Finally, we can use this value to ask for the metadata field containing authors in the metadatavalue table:

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