Helper SQL functions for DSpace

If you are making custom SQL queries against the DSpace database, they can get very complex due to numerous joins between various levels of DSpace objects (bitstream, bundle, item, collection, community). These helper functions contain the joins so you don't have to write them every time. In other words, using one of these functions in your query saves you from typing the body of the function in your query.

Naming convention: bitstream2item5(bitstream_id), returns item id (resource_id), works on DSpace 5.x

Example usage:

SELECT bitstream2item5(123);

DSpace 5

Overview

argument → result ↓	bitstream	bundle	item	collection	community
bitstream	-	-	-	-	-
bundle		-	-	-	-
item	bitstream2item5 bitstream2itemhandle5		item2itemhandle5 itemhandle2item5	-	-
collection			item2collection5 item2collectionhandle5 itemhandle2collectionhandle5		-
community

Create functions

CREATE OR REPLACE FUNCTION bitstream2item5(integer) RETURNS integer
AS 'SELECT item2bundle.item_id
FROM bundle2bitstream, item2bundle
WHERE item2bundle.bundle_id = bundle2bitstream.bundle_id
AND bundle2bitstream.bitstream_id = $1'
LANGUAGE SQL  STABLE  RETURNS NULL ON NULL INPUT;

CREATE OR REPLACE FUNCTION bitstream2itemhandle5(integer) RETURNS varchar
AS 'SELECT handle
FROM bundle2bitstream, item2bundle, handle
WHERE handle.resource_type_id = 2
AND handle.resource_id = item2bundle.item_id
AND item2bundle.bundle_id = bundle2bitstream.bundle_id
AND bundle2bitstream.bitstream_id = $1'
LANGUAGE SQL  STABLE  RETURNS NULL ON NULL INPUT;

CREATE OR REPLACE FUNCTION item2itemhandle5(integer) RETURNS varchar
AS 'SELECT handle
FROM handle
WHERE handle.resource_type_id = 2
AND handle.resource_id = $1'
LANGUAGE SQL  STABLE  RETURNS NULL ON NULL INPUT;

CREATE OR REPLACE FUNCTION item2collection5(integer) RETURNS integer
AS 'SELECT collection2item.collection_id
FROM collection2item
WHERE collection2item.item_id = $1'
LANGUAGE SQL  STABLE  RETURNS NULL ON NULL INPUT;

CREATE OR REPLACE FUNCTION item2collectionhandle5(integer) RETURNS varchar
AS 'SELECT handle
FROM collection2item, handle
WHERE handle.resource_type_id = 3
AND handle.resource_id = collection2item.collection_id
AND collection2item.item_id = $1'
LANGUAGE SQL  STABLE  RETURNS NULL ON NULL INPUT;

CREATE OR REPLACE FUNCTION itemhandle2collectionhandle5(varchar) RETURNS varchar
AS 'SELECT handle
FROM collection2item, handle
WHERE handle.resource_type_id = 3
AND handle.resource_id = collection2item.collection_id
AND collection2item.item_id = (
  SELECT resource_id
  FROM handle
  WHERE handle.resource_type_id = 2
  AND handle = $1
)'
LANGUAGE SQL  STABLE  RETURNS NULL ON NULL INPUT;

CREATE OR REPLACE FUNCTION itemhandle2item5(varchar) RETURNS integer
AS 'SELECT resource_id
  FROM handle
  WHERE handle.resource_type_id = 2
  AND handle = $1'
LANGUAGE SQL  STABLE  RETURNS NULL ON NULL INPUT;

Drop functions

DROP FUNCTION bitstream2item5;
DROP FUNCTION bitstream2itemhandle5;
DROP FUNCTION item2itemhandle5;
DROP FUNCTION item2collection5;
DROP FUNCTION item2collectionhandle5;
DROP FUNCTION itemhandle2collectionhandle5;
DROP FUNCTION itemhandle2item5;

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Helper SQL functions for DSpace

DSpace 5

Overview

Create functions

Drop functions