Questions tagged [relation]
The relation tag has no usage guidance.
48
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16
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Storing OSM relations correctly as geometry in BQ
I am looking at the best/efficient way to decompose OSM relations and store as geography, currently I am using:
https://raw.githubusercontent.com/tyrasd/osmtogeojson/gh-pages/osmtogeojson.js
to ...
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18
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Relation QGIS: get_feature
I have 2 layers (1 polygon / 1 no-geometry (aType)). I have a relation between them.
As we know, we can display 1 value from the related layer via layer property -> Attributes Form.
In the widget ...
- 467
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1
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38
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QGIS - Avoid duplicates on Value-Relation widget
In QGIS, I'm working with two layers that are related to each other through the value-relation widget.
Layer 1: TEST
fields: "id"; "LIB"; "odc_ID"; "Code"
...
- 753
1
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1
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73
views
Fetch multiple fields in relation_aggregate expression
In the QGIS 3.34+ expression builder, how could one use the expression parameter in the relation_aggregate to fetch multiple fields?
E.g.:
relation_aggregate(
relation:= 'my_relation',
...
- 10.5k
2
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77
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QGIS Layer field expression in Polymorphic Relation evaluates to NULL
In QGIS 3.34.3, according to the doc:
Layer expression evaluates to a unique identifier of the layer. This can be the layer name @layer_name, the layer id @layer_id, the layer’s table name decode_uri(...
- 10.5k
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50
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Using resolved values as a label in child table using only the defined Value Relation
I have a "Value Relation" defined to a parent table from a child one in QGIS 3.34.3:
The attribute table shows the resolved value (species name) correctly:
Same when I use the "...
- 10.5k
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84
views
QGIS relation reference widget filter between child (point layer) and parent table (no geometry)
I have two PostGIS layers in QGIS 3.28, they are in a 1-N relation (association):
layer A (parent) without geometry (table)
layer B (child) with point geometry
Both A and B layers have the codsede ...
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1
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81
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Setting relations in QGIS not working in QField
I have a set two relation in my QGIS project. One relation called 'Photos' and the other called 'Attitude'. Though in QGIS desktop it seems to work fine but when I transfer it in Qfield it doesn't ...
1
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1
answer
138
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QGIS export layer relations from one project to another
I have a .qgz project with a spatial layer and two non-spatial layers, primarily created for data collection. All the three layers are saved in a single .gpkg file and the non-spatial layers are ...
- 163
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11
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Project Sync-ing doesn't work in tablet as in the phones Qfield app
I have a project in QGIS and I'd made some relations in it, but one of (a non geometric layer, named Evaluate, which is based on a Vector layers (point) order number. This layer contains trees) those ...
2
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1
answer
62
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Getting the result automatically when only one match with Value relation in QGIS
I have a project that comprises three crucial layers:
A SpatiaLite layer named 'HABITATS_POLY'
A layer without geometry named 'CORRESPONDANCES'
A database named "BD_CORINE"
When a code is ...
- 753
2
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0
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32
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QGIS not showing cascading relations in identify
I have 3 tables that are related as shown in figure below:
I added two relaltions. The first one between Table1 and Table2 and the other one between Table2 and Table3 as shown in figure below:
On ...
- 83
5
votes
1
answer
170
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QGIS - many to many relations - query expression
I have a polygon layer with area geometries of parcels and tables with contracts, with owners / users linked by means of a link table in many to many relationships. This is because some parcels may ...
- 537
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72
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How to set up a filter in a value relation of a child of a parent-layer depending on attributes in parent layer
I have a 1:n relation between (postgresql-) parent-layer "parentlayer" and a child-layer "childlayer" based on parent-layer-field "pl_uuid" referencing child-layer-field &...
- 581
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46
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QGIS - comma separated values or link table - m-n relations
Is there a way in QGIS to assign multiple values to another value without creating additional columns? Using the example of owners to parcels, I would like to set the reference to several parcels in ...
- 537
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55
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QGIS values from 1:n related table to parent attribute table
I'm confused since I don't really get the difference between a form and a table in QGIS. I've successfully created multiple one to many relations between my parent shapefile and child excel sheets ...
- 229
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50
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QGIS: Update parent attribute based on most recent child
To describe the situation, I have parent geopackage layer for 'Trees' which is related to a child geopackage table 'tree_inspections'. So each tree can have many inspections. I use a foreign key '...
- 13
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93
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Calculate a field in a parent table when a child record is created or modified using QGIS
In QGIS, I have a feature class named "Water_Crossing" that has a field named "Modified".
I have a relation set up from "Water_Crossing" to 3 child tables "...
- 91
1
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41
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QGIS: Value relation forms
Is it possible to set default value to parent, based on child entry? I know how to do it from parent to child, but I want to do it in reverse. I have two CSV files with values. First I want to edit ...
- 358
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2
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358
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Geometry extraction from osm.pbf file using relation id with ogr2ogr
What works
If I need a GeoJSON file with the OpenStreetMap borders of Liechtenstein, I download liechtenstein-latest.osm.pbf from GeoFabrik:
curl https://download.geofabrik.de/europe/liechtenstein-...
- 2,224
2
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32
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Displaying more than 100 entries in Relation Reference Widget dropdown in QGIS
I am using QGIS 3.28, and I've encountered an issue with the Relation Reference Widget. In the form view, the dropdown menu of the Relation Reference Widget only displays 100 entries.
Is there a way ...
- 8,338
3
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79
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Using get_feature() function on layer while editing in QGIS
In QGIS, I am trying to update a feature based on entries made on a nested form (relation).
Considering:
Layer1 has Field1 that should capture the value of Field 2, and field in Layer2
Layer2 is ...
- 567
2
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1
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437
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Extracting relations with osmnx?
I am using osmnx package https://osmnx.readthedocs.io/en/stable/osmnx.html
to extract data from OSM. I aim to obtain relations from the cyclist node network in Flanders. After some info about tagging, ...
- 21
1
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1
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82
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QGIS relation reference widget shows an empty list instead of values
I'm trying to set up a QField project to entry data from a bird watch project.
I have a few layers which I would like to connect with the ID of the tour.
I am using relation reference widgets.
The ...
- 11
5
votes
2
answers
253
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QGIS aggregate - filter by newest date
i have two one-to-may related layers (relation name: tree_observation) parent: trees and child: obeservations. The trees should be revisited on a regular base and for each observation a new child ...
- 3,022
2
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98
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QGIS Relation reference widget performance
I have a relation 1:1 on a table with limited parcels (ca 2000 rows) related to huge table on national level (ca 22 million rows), PostgreSQL 14 with PostGIS. Smaller table is used with view to show ...
- 308
2
votes
1
answer
441
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QGIS - Relations - Update parent from child / child from parent
The functioning of my project under QGIS is based on the use of information between parent and child (relation layers).
I need to access specific information to control visibility of containers and ...
- 753
4
votes
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403
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QGIS - Value relation values based on geometry
I am having a problem with last part of defining values in geopackage.
I have created relation values based on field values (drop-down values). Last one I want to create, is to make relation based on ...
- 358
1
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1k
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ArcGIS Pro Attribute Rule to pass a value from child to parent
I have an ArcGIS geodatabase with a parent feature class related to a child stand alone table containing the various inspections made on each parent feature. Primary key is GlobalID and foreign key is ...
- 33
3
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1
answer
262
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Using relations
I am using QGIS, version 3.24.0. I have a shapefile called "Map_CorrectionDEF", uniquely identify by fields "GID" and "unitcode". It is a grid cell, in which the field &...
- 618