Syntax of queries to the data base

Summary of existing directives:

• the queries to the data base included in the body of the mail to bdbquery@obs-besancon.fr must be inserted between the two tags <REQUEST> and <EREQUEST> ; this is required to account for future developments allowing other, more evolved, types of requests to the data base according to different criteria.
  
• instructions are supplied one per line ; they can be of two different types:
  • either they specify the identifier of a star in a given star catalogue;
  • or they allow to specify selection criteria (choice of a catalogue or of one or several data types) on the requested informations to the data base for the stars whose identifiers are supplied in the following lines ; the criterion will then apply to all the stars which follow till a selection criterion of the same type is encountered (see example) ;
    
• it is possible to leave blank lines in the body of the e-mail for clarity ;
• it is possible to insert comments using lines starting with a sharp sign (#)  ;
• it is possible to leave blanks at the beginning of directive lines ;
• in the case of an instruction specifying a star, the general syntax of a line is then :
          CATALOGUE_ID=star_id
    see names of possible catalogue identifiers
  the format of the identifier of the star depends on the catalogue ;
  examples :

  <REQUEST> HD=152270 VN=V444 Cyg VN=ups Sgr VN=gam Dor VN=nu. Cen CCDM=00003+6557 WDS=17320-2300 SAO=233457 ADS=8337 IDS=06345N0208 BD=+33 2452 HIC=71352 AGK23=+30 3 <EREQUEST>

• in the case of a line containing an instruction selecting informations, you can specify that you want :
  • either the data of a given multiple star catalogue (Worley, Hipparcos, Cesmid,...) ; the general syntax of the instruction is :
        CATALOGUE=catalogue_name
    see the list of presently available multiple star catalogues in the bdb database.
    If you want to get anew the data of all the catalogues for the stars that follow, the instruction is then :
       CATALOGUE=all
    This is the default value at the beginning of the list.
  • or choose one or more data types (astrometric data, photometric data, eclipsing binary data, ...) in the selected catalogue or for the whole catalogues. The general syntax of the instruction is :

       DATATYPE=list_of_data_types
    

    The data types are identified by a letter :
    a   (astrometric),
    p   (photometric),
    e   (eclipsing binary stars),
    s   (spectral data),
    i   (charts and curves),
    l   or all (all types of data ; default value)
    
    To request several data types, just seperate the identifiers with commas ; example :

       DATATYPE=a,p,e
    

  IMPORTANT :
  DATATYPE=... and CATALOGUE=... directives are valid for all stars whose identifiers are supplied thereafter until an other DATATYPE=... or CATALOGUE=... respectively is encountered (see example).