Cool!
On 6/22/17 7:58 AM, Riyafa Abdul Hameed wrote:
Dear all,
Thank you very much. I hadn't thought of an AnyObject type. Now I am
able to parse GeoJSON using the following:
DROP DATAVERSE GeoData IF EXISTS;
CREATE DATAVERSE GeoData;
USE GeoData;
CREATE TYPE AnyObject AS {};
CREATE TYPE FeatureType AS {
id: UUID,
`type`: string,
`geometry`: AnyObject,
properties: AnyObject
};
CREATE DATASET Geometries (FeatureType) PRIMARY KEY id autogenerated;
INSERT INTO Geometries ([
{
"type":"Feature",
"geometry":{
"type":"Point",
"coordinates":[
-118.40,
33.93
]
},
"properties":{
"code":"LAX",
"elevation":38
}
}
]);
SELECT * FROM Geometries;
Thanks again.
Riyafa
On 22 June 2017 at 02:37, Ahmed Eldawy <[email protected]
<mailto:[email protected]>> wrote:
Hi Riyafa,
I think you should use the terms *feature* and *geometry* to avoid
confusion like the following example.
CREATE TYPE AnyObject AS {};
CREATE TYPE *FeatureType* AS {
`type`: string,
the_geom: *geometry*,
properties: AnyObject
};
The internal 'geometry' attribute is what holds the shape geometry
while the outer FeatureType associates additional attributes and
properties to that geometry.
As we discussed in our last call, the first step is to parse
GeoJSON as a regular JSON file and then parse the geometry using a
UDF. In this case, you might have something like:
CREATE TYPE *FeatureType* AS {
`type`: string,
the_geom: *AnyObject*,
properties: AnyObject
};
This will allow you to parse the file without modifying the
existing JSON parser. Then, you can define a UDF called
"ParseGeoJSON" which takes as input the "the_geom" attribute and
returns a parsed geometry attribute.
The next step should avoid this additional step and should
automatically detect and parse the geometry attribute directly
from GeoJJSON.
Thanks
Ahmed
On Wed, Jun 21, 2017 at 11:40 AM, Yingyi Bu <[email protected]
<mailto:[email protected]>> wrote:
>> type appears to be keyword
`type` would make it valid.
>> We can't use the defining type within the same type
recursively (ie.
GeometryType within GeometryType)
We don't support recursive type definition.
>> The type object cannot be resolved
We don't have a builtin name for a completely open type, but
you can
define one.
What you can do is:
CREATE TYPE AnyObject AS {};
CREATE TYPE GeometryType AS {
`type`: string,
geometry: SomeType;
properties: AnyObject
}
Best,
Yingyi
On Wed, Jun 21, 2017 at 6:33 AM, Mike Carey <[email protected]
<mailto:[email protected]>> wrote:
> One approach would be to be silent about properties - and
then it could be
> there anyway - however, that wouldn't allow you to state the
requirement
> (?) that it must be called properties and/or that it must be
an object (not
> a scalar). That could work for now, perhaps? We need to
have an "any
> record type" type name - we've noted a desire for that -
unfortunately we
> don't have one I don't think. I believe the concept is
there inside the
> code, in the type-related areas, but we don't have a keyword
like name for
> it. (@Yingyi - comments?) And we do also have a
restriction (at the type
> level) that precludes recursion (regular or mutual) in type
definitions; we
> probably need to do something about that someday as well.
>
> In the meantime, these things could be handled (weakly) by
documenting
> what's expected/allowed in this setting.
>
> Cheers,
>
> Mike
>
> PS - I wonder if JSON Schema has the expressiveness for this?
>
> On 6/21/17 2:26 AM, Riyafa Abdul Hameed wrote:
>
> Hi,
>
> I would like to parse the following or any GeoJSON type[1]
to a record in
> AsterixDB:
> {
> "type":"Feature",
> "geometry":{
> "type":"Point",
> "coordinates":[
> -118.40,
> 33.93
> ]
> },
> "properties":{
> "code":"LAX",
> "elevation":38
> }
> }
>
> The value of properties is optional and is a variable that
is it can be
> any type of object. What is the most suitable datatype to
use to represent
> properties in this case?
> Is something like the following possible?
>
> CREATE TYPE GeometryType AS {
> type: string,
> geometry: GeometryType,
> properties: object
> };
>
> I came up with the above because there's a derived type
called objects[2]
> in AsterixDB. The above doesn't work because of the
following reasons:
>
> - type appears to be keyword
> - We can't use the defining type within the same type
recursively (ie.
> GeometryType within GeometryType)
> - The type object cannot be resolved
>
> Any suggestions on how a GeoJSON can be parsed into AsterixDB?
>
> [1] https://tools.ietf.org/html/rfc7946
<https://tools.ietf.org/html/rfc7946>
> [2]
https://ci.apache.org/projects/asterixdb/datamodel.html#Deri
<https://ci.apache.org/projects/asterixdb/datamodel.html#Deri>
> vedTypesObject
>
> Thank you
> Yours sincerely,
> Riyafa
>
>
>
