[Geoserver-users] WFS query with limit and offset

Maria_Krommyda · August 20, 2018, 11:21am

Hello everyone,

I have set up a GeoMesa Accumulo datastore and I would like to fetch the data using a limit and an offset (with some sorting if it is required) but I have not managed to find if this is possible or not.
I have found only this http://osgeo-org.1560.x6.nabble.com/Specifying-an-offset-in-a-WFS-GetFeature-request-td3802601.html but it is from 2009 and I cannot find any follow-up.

Can you please let me know if this is possible or not?
Or if there is any tutorial/documentation about what can be used as filter in a WFS GetFeature request?

Thank you very much for you time.

Best regards,
Maria.

ianturton · August 20, 2018, 12:52pm

This blog post (https://www.geo-solutions.it/blog/wfs-for-the-masses-adding-support-for-paging-and-sorting-in-geoserver/) seems to cover this. So it looks like since 2.1 GeoServer has allowed you to make queries like:

http://localhost:8080/geoserver/topp/ows?service=WFS&version=1.0.0&request=GetFeature
&typeName=topp:states&outputFormat=csv&propertyName=STATE_NAME,PERSONS
&maxFeatures=10&startIndex=10&sortBy=PERSONS%20D

I think the syntax changed for WFS 2.0 but I can’t find a reference just now

Ian

···

Ian Turton

Maria_Krommyda · August 20, 2018, 1:31pm

Hello Ian,

Thank you very much for your fast response.
I read the blog post that you mentioned and it helped greatly, but I still have one question.

What I have not understood is if the sorting is mandatory, to ensure the smooth retrieval of the information, or not.
I feel that the post implies that it is not mandatory, and some testing that I did seems to confirm that, but I would like to know for sure.
I think that if not specified, the sorting is done by the back end on the first propertyName?

Thank you once more for your time and the helpful information.

Best regards,
Maria.

Στις 3:52 μ.μ. Δευτέρα, 20 Αυγούστου 2018, ο/η Ian Turton ijturton@anonymised.com έγραψε:

This blog post (https://www.geo-solutions.it/blog/wfs-for-the-masses-adding-support-for-paging-and-sorting-in-geoserver/) seems to cover this. So it looks like since 2.1 GeoServer has allowed you to make queries like:

http://localhost:8080/geoserver/topp/ows?service=WFS&version=1.0.0&request=GetFeature
&typeName=topp:states&outputFormat=csv&propertyName=STATE_NAME,PERSONS
&maxFeatures=10&startIndex=10&sortBy=PERSONS%20D

I think the syntax changed for WFS 2.0 but I can’t find a reference just now

Ian

On Mon, 20 Aug 2018 at 13:05, Maria Krommyda via Geoserver-users <geoserver-users@lists.sourceforge.net> wrote:

Hello everyone,

I have set up a GeoMesa Accumulo datastore and I would like to fetch the data using a limit and an offset (with some sorting if it is required) but I have not managed to find if this is possible or not.
I have found only this http://osgeo-org.1560.x6.nabble.com/Specifying-an-offset-in-a-WFS-GetFeature-request-td3802601.html but it is from 2009 and I cannot find any follow-up.

Can you please let me know if this is possible or not?
Or if there is any tutorial/documentation about what can be used as filter in a WFS GetFeature request?

Thank you very much for you time.

Best regards,
Maria.

Check out the vibrant tech community on one of the world’s most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot_______________________________________________
Geoserver-users mailing list

Please make sure you read the following two resources before posting to this list:

Earning your support instead of buying it, but Ian Turton: http://www.ianturton.com/talks/foss4g.html#/

The GeoServer user list posting guidelines: http://geoserver.org/comm/userlist-guidelines.html

If you want to request a feature or an improvement, also see this: https://github.com/geoserver/geoserver/wiki/Successfully-requesting-and-integrating-new-features-and-improvements-in-GeoServer

Geoserver-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/geoserver-users

–

Ian Turton

ianturton · August 20, 2018, 4:12pm

If you don’t specify a sort column(s) you will get the features in FID order which may or may not be fixed depending on the backend. I would always set the sort attribute when paging.

Ian

···

Ian Turton

Maria_Krommyda · August 21, 2018, 8:08am

Thank you very much for this clarification.

Is there a document/tutorial where I can find all the parameters that can be used in a GeoServer URI when querying the data?

Best regards,
Maria.

Στις 7:12 μ.μ. Δευτέρα, 20 Αυγούστου 2018, ο/η Ian Turton ijturton@anonymised.com έγραψε:

If you don’t specify a sort column(s) you will get the features in FID order which may or may not be fixed depending on the backend. I would always set the sort attribute when paging.

Ian

On Mon, 20 Aug 2018 at 14:32, Maria Krommyda <mariakr1989@anonymised.com> wrote:

Hello Ian,

Thank you very much for your fast response.
I read the blog post that you mentioned and it helped greatly, but I still have one question.

What I have not understood is if the sorting is mandatory, to ensure the smooth retrieval of the information, or not.
I feel that the post implies that it is not mandatory, and some testing that I did seems to confirm that, but I would like to know for sure.
I think that if not specified, the sorting is done by the back end on the first propertyName?

Thank you once more for your time and the helpful information.

Best regards,
Maria.

Στις 3:52 μ.μ. Δευτέρα, 20 Αυγούστου 2018, ο/η Ian Turton <ijturton@anonymised.com> έγραψε:

This blog post (https://www.geo-solutions.it/blog/wfs-for-the-masses-adding-support-for-paging-and-sorting-in-geoserver/) seems to cover this. So it looks like since 2.1 GeoServer has allowed you to make queries like:

http://localhost:8080/geoserver/topp/ows?service=WFS&version=1.0.0&request=GetFeature
&typeName=topp:states&outputFormat=csv&propertyName=STATE_NAME,PERSONS
&maxFeatures=10&startIndex=10&sortBy=PERSONS%20D

I think the syntax changed for WFS 2.0 but I can’t find a reference just now

Ian

On Mon, 20 Aug 2018 at 13:05, Maria Krommyda via Geoserver-users <geoserver-users@lists.sourceforge.net> wrote:

Hello everyone,

I have set up a GeoMesa Accumulo datastore and I would like to fetch the data using a limit and an offset (with some sorting if it is required) but I have not managed to find if this is possible or not.
I have found only this http://osgeo-org.1560.x6.nabble.com/Specifying-an-offset-in-a-WFS-GetFeature-request-td3802601.html but it is from 2009 and I cannot find any follow-up.

Can you please let me know if this is possible or not?
Or if there is any tutorial/documentation about what can be used as filter in a WFS GetFeature request?

Thank you very much for you time.

Best regards,
Maria.

Check out the vibrant tech community on one of the world’s most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot_______________________________________________
Geoserver-users mailing list

Please make sure you read the following two resources before posting to this list:

Earning your support instead of buying it, but Ian Turton: http://www.ianturton.com/talks/foss4g.html#/

The GeoServer user list posting guidelines: http://geoserver.org/comm/userlist-guidelines.html

If you want to request a feature or an improvement, also see this: https://github.com/geoserver/geoserver/wiki/Successfully-requesting-and-integrating-new-features-and-improvements-in-GeoServer

Geoserver-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/geoserver-users

–

Ian Turton

–

Ian Turton