Search/Retrieve via URL
Search / Retrieve via URL (SRU ) is a technical standard for libraries, which was created as part of the initiative Z39.50 International Next Generation ( ZING ) to create a modern development of the Z39.50 protocol. The related techniques based on established Internet standards such as URI and XML, which are in contrast to Z39.50 distributed about librarianship beyond. These include:
- SRW ( Search / Retrieve for the Web )
- CQL (Common Query Language)
- ZOOM ( Z39.50 Object Orientation Model)
- Ez3950 and ZeeRex.
SRW
A core component of the ZING initiative is the Search / Retrieve Web Service protocol ( SRW ), allows the Z39.50 similar queries over HTTP using simple HTTP GET requests or via the SOAP protocol. The queries are formulated in the query language CQL and returned the results as XML. SRW was developed and published by the Library of Congress.
In the following example, the CQL query is dc.title = security to a host of the British Library found. The metadata should be delivered in the Dublin Core format. The other transfer parameters affect the desired number of hits.
- Http://herbie.bl.uk:9080/cgi-bin/blils.cgi?query=dc.title=security&recordSchema=DC&maximumRecords=10&startRecord=1
Here is a complete example with request and response:
- Http://www.theeuropeanlibrary.org/sru/sru.pl?query=dc.author=marx,karl&recordSchema=DC&maximumRecords=1
< srw: searchRetrieveResponse
xmlns: srw = " http://www.loc.gov/zing/srw/ "
xmlns: srw_dc = "info: srw/schema/1/dc-v1.1 "
xmlns: dc = " http://purl.org/dc/elements/1.1/ "
xmlns: diag = " http://www.loc.gov/zing/srw/diagnostic/ "
xmlns: dcx = " http://krait.kb.nl/coop/tel/handbook/telterms.html "
xmlns: phone = " http://krait.kb.nl/coop/tel/handbook/telterms.html "
xmlns: rdf = " # http://www.w3.org/1999/02/22-rdf-syntax-ns "
xmlns: xsi = " http://www.w3.org/2001/XMLSchema-instance "
xmlns: mods = " http://www.loc.gov/mods "
xmlns: lib = " http://krait.kb.nl/coop/tel/handbook/telterms.html "
xmlns: cld = " http://www.ukoln.ac.uk/metadata/rslp/schema/ "
xmlns: dcterms = " http://purl.org/dc/terms/ " >
SRU offers slightly less functionality than SRW, but it comes without SOAP and is thus significantly slimmer.