Common Command Language

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The Common Command Language (CCL) is a query language for information retrieval systems that was defined in 1993 in the ISO standard 8777. CCL tries to standardize search commands in databases so that users do not have to learn a new language for each database. CCL can still be used directly in many OPACs . However, with the advent of graphical user interfaces, the retrieval language has been partially forgotten. Critics (e.g. Garman) argue that a uniform language for search queries is no longer appropriate. The lack of documentation in existing OPACs and databases and the not always standard-compliant implementation also contribute to the low distribution.

An extension of the CCL is the Common Query Language (CQL) of the ZING initiative. In the area of web services there are other query languages ​​that are not intended for end users, but for communication between different computer programs .

The standard of the same name planned by the American National Standards Institute (Z39.58) from 1992 was withdrawn with the appearance of the CCL.

Components

In principle, requests in CCL consist of a number of assignments of field abbreviations and search values ​​that can be linked using Boolean operators and brackets. In addition, some special functions are possible.

  • Boolean operators: ANDor +, ORor |, NOTor~
  • Proximity operators: WTI=Arbeit %1 Zukunftsearches for titles with at most one word between the words “work” and “future” (any order) for a given order instead of %the exclamation mark ( !).
  • Truncation and placeholders:
    • !: any character
    • #: one or no arbitrary character
    • ?or *: any number of characters at the beginning or end of a word
  • Value ranges: WJA=2000 -> 2003restricts the search to publication years from 2000 to 2003

The field abbreviations depend on the respective database.

See also

literature

  • Nancy Garman: Whatever happened to common command language? . In: Online . November 1995, pp. 7-8.
  • ISO 8777: Information and documentation - Commands for interactive text searching , 1993.
  • M. Purser: The Euronet Diane Network for Information Retrieval . In: Information Technology: Research and Development . 1, 1982, pp. 197-216.
  • Yves Vander Auwera, Luc Bernard: New proposal for a common command language in information systems . In: ACM SIGMOD Record . 13, No. 1, September 1982, pp. 51-78 doi : 10.1145 / 984514.984518 .
  • Alan E. Negus: Development of the Euronet-Diane Common Command Language . In: Proceedings of the 3rd International Online Information Meeting . Learned Information, Oxford 1979, pp. 95-98 (see also articles citing this article ).
  • Alan E. Negus: Euronet Guide Line - Standard commands for retrieval systems . INSPEC - The Institution of Electrical Engineers, London 1977.
  • Alan E. Negus, JL Hall: Towards an effective on-line reference retrieval system . In: Information Storage and Retrieval . 7, No. 6, 1971, pp. 249-270, doi : 10.1016 / 0020-0271 (71) 90018-0 .

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