[OSM-dev] JOSM: Several tags with same key

Pierre-André Jacquod pjacquod at alumni.ethz.ch
Fri Apr 3 06:31:42 BST 2009


Stefan de Konink wrote:
> Andy Robinson (blackadder-lists) wrote:
>> The convention is to separate multiple values for the same key with a
>> semicolon.
> ...and that semantical addition breaks querying for any tool [including 
> your database] that follows context free grammar. XML well defines that 
> you can use multiple entities, that this API0.6 'wisdom' is still about 
> removing multiple keys is not only plain stupid, but also inconsistent 
> with previous behavior and queryability of the domain.
> Again, the only right way to do is preventing duplicate entries, which 
> can easily be enforced using unique(objectid, key, value).
> I hope anyone will see the implications for XAPI (the OSM replacements 
> that looks like XPath) before it is too late, and what happens if you 
> want to find for example amenities that have two values delimited by ';' 
> and will not show up with any of these values, unless by default the 
> search operation is done by 'LIKE'.
> Stefan
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