adql: prefixes in TAP_SCHEMA.columns

[Patrick Dowler]

On 02/07/14 07:09 AM, Markus Demleitner wrote:
> There is yet another problem.  I've been putting things like
>
> VARCHAR(*)
>
> into my columns forever.  Given there's the size I suddenly realised
> that that's probably wrong.  So, what's the official TAP_SCHEMA
> mapping for VARCHAR(*)?  Frankly, I'd be all for datatype=VARCHAR(*),
> size=NULL, but what what's size for, then? (nb size is an integer in
> TAP_SCHEMA)

tap_schema: datatype=VARCHAR size=NULL

votable: datatype="char" arraysize="*"

The * in the latter is implied by the VAR. It's ugly because the mapping 
from SQL to VOTable types is not trivial, as shown by:

tap_schema: datatype=VARCHAR size=128

votable: datatype="char" arraysize="128*"

aka VARCHAR(128) in most DBs.




-- 

Patrick Dowler
Canadian Astronomy Data Centre
National Research Council Canada
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