i thought it was more easy ...

In fact , i don't use a GPS because these points don't need precision : they are only used to identify the parcels . And i would like to catch their identity ( a number for each parcel and the owner ) if possible with a dynamic spatialjoin...

With booth data ( number of parcel and name of owner ) , i could talk with the fisc administration :-)

Randy was right ...i didn't have the same EPSG for the two layers . It's now OK ! but without the feature "dynamic" .

Indeed , i would avoid building many temporaries layers and i thought it existed a plugin for this " dynamic" feature.

If no , i will ask my users to make spatialjoins some time to time ...

Waiting , i will try the solution of Bernd...

Thank you anyway !


Le 21/12/2016 à 17:46, Bernd Vogelgesang a écrit :

for me this sounds more like he is getting new points once in a while and
wants to join those attributes to the new points "automatically" from the
parcel layer.

The biggest problem for users is to rethink the workflow from the end to
the beginning and to know the limitations.

The outcome should be a point layer with the polygons attributes. If those
points (layer A) are from GPS as Randy assumes, they have to be
reprojected to the parcels layer (layer B) before being able to join them
spatially(layer C). The spatial join in the toolbox produces layer D.

Most probably, the resulting layer D is going to to be edited in some way
(adding notes about size, the progress, classifications, whatever), so you will have to find a way to preserve those new attribute while being able to
add new points without much trouble.

The processing toolbox is a good way to do these steps, though it produces
a lot of temporary files cluttering the project.

A better way for all those repetitive tasks, is to use the graphical
modeller, to create a workflow which only has to be triggered once new
points come in, and the resulting file can be saved as new a file e.g.
with the current date in the name, so you have kind of an archive and do not
overwrite previous files (and destroy your work in case something goes

So I can imagine a model with input layer A (new points in WGS84 without attributes) and a parcel layer B (in whatever projection).
reproject layer A and C will be created as an intermediate step.

Next input layer is the latest result layer D, reprojected and with attributes. Merge layer C and D -> E. Now delete all columns which are from layer B (from the last spatial join. Unfortunately, you can only delete one field at a time in the modeller, so you'll will have to add the command several times in a row to the model) -> Fn
Do the spatial join of Fn with B.

The last result G will now hold all points with the corresponding parcel info plus additional fields you might have added to the points.
G will be the input D in the next run with fresh points.

So, do not add new points to the already existing collection of points in WGS84 (it is never save to edit layers without backup), but just import them as a new input set and then run the model with the parcel layer and the last result layer.

The modeller is not as intuitive as it should be, but it can save you a lot of time once you managed to set up a model.

Maybe I was completely wrong analysing the problem, but maybe someone else has the problem that fits to my solution ;)

Am 21.12.2016, 14:07 Uhr, schrieb Randal Hale

2 things:

1. In QGIS there is a processing toolbox (I assume you are one something as new as version 2.14.8). Open it (it's at the top -> Processing -> Toolbox). You can search for tools. Search for "join" and you should see a "Join Attributes by location". This is a spatial join.

2. THE MOST IMPORTANT THING. You mentioned you had collected points with a GPS. Possibly these points are in EPSG:4326. I'm going to guess that your parcel layer isn't. If you right click your parcel layer (in the layers panel) it will allow you to select properties. On the General Tab you will see the Coordinate Reference System mentioned and many times it is something like EPSG:xxxx . A Spatial Join must have the layers in the same coordinate system.

If it is different - Right Click on your GPS points and "Save as". When the "Save vector layer as...." window comes up. Save it as a shapefile and MOST IMPORTANTLY change the CRS to match your parcel layer. Click on the small globe (that appears to be wearing a hat) and in the filter type in the number you see for your parcels. You can then select that projection and Save your file. It should save. You can then perform the "join by location".

It should work. You are very close though so don't worry.


On 12/21/2016 01:24 AM, Erwan Conseil wrote:
In my layer B , I have the name of the owner and the number of the parcel : this number , a polygon , have a WKT location . All this is in a SHP . As I grab points in layer A directly in Qgis (2.18) , I have also a SHP . And i need a dynamic join because I have no desire to make the spatial join each time...

Le 21 déc. 2016 à 01:30, Randal Hale <rjh...@northrivergeographic.com> a écrit :

In your layer B - Do the Names of the Owners have a location (like a tax parcel) or are they a spreadsheet (like Microsoft Excel)?


On 12/20/2016 06:03 PM, Laurent Bourlet wrote:
Hi at all

I'm a beginner in Qgis and i would make a dynamic spatialjoin.
In fact , i have created a vector layer ( for example A) and i grab points in it when I'm outdoor ( these points are buildings unknowned by the government and so these building are not taxed ...) . I have also a layer (B) with the name of the owners of these lands .
You see what i would ?...
I would have these names transferred as attribut from B to A .
For that , i think about a spatialjoin with a dynamic feature . So i have downloaded the two plugins "reffunction" and "spatialjoin". But i have certainly maked something wrong because i don't succeed ...

Is it the good method ?

And If yes , and if exist a doc about these plugins ...i'll take it :-))



( pour les francophones ...je repère et saisis des points représentants des batiments construits et visibles par Google Map mais inconnus par le cadastre et donc les impôts ...je voudrais donc enrichir la couche de saisie par les références des parcelles et les noms des propriétaires par une jointure spatiale dynamique ..à chaque point saisi , "monte" cette référence )

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North River Geographic Systems, Inc
423.653.3611 rjh...@northrivergeographic.com

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