Hallo Andy
On 2006-1003 10:24:42, Andy Dustman wrote:
> http://dev.mysql.com/doc/refman/5.0/en/supported-spatial-data-formats.html
>
> I think these are OpenGIS formats.
yes and no:
these are the formats returned by the translation functions asBinary
and asText. both take a geometry object and return a representation
in a 'well known' format, which are both different from the internal
representation.
a small python interaction to show the difference (from the mysql client
you don't see anything) (I'm forcing geomFromText(...) to create a
geometry object on the fly)
>>> cr.execute("select geomFromText('POINT(34214.3412 34214.3412)')")
1L
>>> cr.description
(("geomFromText('POINT(34214.3412 34214.3412)')", 253, 25, 8192, 8192, 0, 0),)
>>> cr.fetchone()
('[EMAIL PROTECTED]@',)
>>> cr.execute("select asBinary(geomFromText('POINT(34214.3412 34214.3412)'))")
1L
>>> cr.description
(("asBinary(geomFromText('POINT(34214.3412 34214.3412)'))", 253, 21, 8192,
8192, 0, 0),)
>>> cr.fetchone()
('[EMAIL PROTECTED]@',)
>>>
is the fact that the description field has the same '253' value for both
internal and wkb formats going to be a problem? if I was _using_
mysqldb, I don't see a chance to distinguish the two things. but maybe
_inside_ of mysqldb the distinction is made somehow.
ah, well, you do see that the internal binary representation is
different from the wkb one...
as a user and even more as a library writer, I would not want to have
to write a 'asBinary(<field>)' for each of my geometric fields.
Mario
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