Questions tagged [relation]
The relation tag has no usage guidance.
40
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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 ...
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4
votes
1
answer
140
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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 ...
- 509
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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 &...
- 551
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40
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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 ...
- 509
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29
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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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20
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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 '...
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1
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47
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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
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29
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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 ...
- 348
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1
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156
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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-...
- 1,308
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39
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Relation popup display using Lizmap
The qgis popup shows the relationship records in the correct order based on the ID field, from 1 to 26.
The Lizmap popup instead shows the relationship records backwards, from 26 to 1.
How can this ...
2
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0
answers
27
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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 ...
- 8,196
3
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31
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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 ...
- 557
2
votes
1
answer
202
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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
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40
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Polymorphic relation - Layer field won't get populated
I posted this as an issue on Githhub but I'm wondering if there is a workaround.
Assuming the following relation on a project used in QField:
When digitizing features using a form with polymorphic ...
1
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0
answers
32
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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
153
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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 ...
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2
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67
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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 ...
- 280
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26
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Use displayed values instead of raw data in joined tables
(I believe my question is directly linked to this one, but the answer is incomplete)
I have a large QGIS project with multiple forms using hundreds of "value relations" to create dropdown ...
- 557
2
votes
1
answer
213
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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 ...
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4
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1
answer
287
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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 ...
- 348
1
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1
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767
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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 ...
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3
votes
1
answer
162
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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 &...
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5
votes
1
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322
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Automatically fill in attributes of parent feature in QGIS
I have a data table that holds different information about buildings in a GeoPackage. Different elements of the buildings can be entered, e.g. sometimes I only have the building as a whole, sometimes ...
- 1,588
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59
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Merging queries to return ways/nodes that are within relations matching criteria using Overpass API
Motivation - I am currently processing a number of relations matching criteria and then doing an additional query to get all the ways/nodes within those relations. .
Goal - I'm trying to simplify this ...
- 131
1
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1
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29
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Show selection of point in relation of a vector field?
I have two files,
vector "streets"
a series of point "civic numers" or "address"
I want to select a random street and have the field selection of the relative civic ...
4
votes
2
answers
325
views
QGIS Setup n:m relation to enable cross-layer search
In QGIS I want to set up a n:m relation between two tables "parcels" (polygons) and "owners" (no geometry). Both share a field index1 (containing of numbers and letters) by which ...
- 2,687
1
vote
1
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548
views
Expression-based table relation in QGIS, avoiding joins and relates
In QGIS 3.18. I have two tables, one as a part of a .shp and the other a tab-delimited .txt with no geometry:
my .shp attribute table contains a list of sites, and
my .txt table contains a list of ...
- 1,051
0
votes
0
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55
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Opening one corresponding related table in attribute form for selected feature in multipolygon in QGIS
I have MultiPolygon A with 9 features, each feature should be described by one non-spatial attribute table with 10 - 500 features. I tried to create 9 relations like A-to-Table1, A-to_Table2 ...A-to-...
1
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1
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304
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N:M relation in QGIS with custom form in Qt Designer
The manual: https://docs.qgis.org/3.16/en/docs/user_manual/working_with_vector/attribute_table.html#creating-one-or-many-to-many-relations describes how to create a N:M relation and how to use it with ...
- 61
3
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1
answer
92
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Counting the number of relations
In QGIS I created a one-to-many relation between a polygon layer and a non-geometry table, so it has multiple lines for each feature in the polygon layer. My question now is how can I count how many ...
- 1,082
2
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0
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148
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How to list relationed objects on QGIS expression for HTML tips
I have two layers with an 1-N relationship
The parent layer, "RADAR" is a point layer, while the child layer, "FAIXA_RADAR" is a tabular without geometry layer.
To make feature ...
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1
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1
answer
202
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QGIS best way for capturing features without geometry and child features
I have two (PostGIS) layers in my QGIS (3.18) project and I defined a relation between them.
The first layer PARENT has no geometry.
The second layer CHILD is the child layer and has a geometry.
In ...
- 163
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votes
2
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571
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Handling multiple selections result in "Value Relation Widget" in QGIS
Using the "Allow multiple selections" in the "Value Relation Widget" results in {value1,value2,...}. But arrays in QGIS are written like ['value1','value2',...].
How do I handle ...
- 8,196
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1
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233
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Where are QuickOSM relations?
When I use quickOSM in QGIS to download OSM data, I check the "relations" option, but then?
My need is the following :
Download OSM data for a specific area
In the table for the "point&...
- 21
2
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0
answers
72
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QGIS Hidden attributes not hidden in Relations
I have a PostGIS view, which a referencing layer for another layer for many to one relation in QGIS. I have hidden the following fields id, table_name, oid of the postgis view so that the user would ...
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1
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2
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170
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QGIS Atlas attributes
So I have two layers. First one is line layer (columns: id, length, address_id) and atlas is connected to it so when I change objects, map is zooming to next line. Secound is point layer (columns: ...
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238
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QGIS N:M relations - possibility to edit multiple features?
I have a working QGIS project with multiple relations and all is well until I try the Toggle multi edit mode for N:M relations. I'm working with QGIS 3.10+ (3.14.16) and Windows and PostGIS.
Is it ...
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1
answer
175
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Report with relations
I collected field data containing general information about signpost sites (location, altitude, image) and specific information of the particular signs mounted to the singpost (image, direction). One ...
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1
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154
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QGIS Cloud and relations
Does publishing to QGIS cloud preserve the established relations (1 to many relation) between layers? On the web map, can you see the embedded form of the Parent layer in the Child layer, for example?
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1
answer
1k
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1-n relationship by location in QGIS
I have a polygon layer and a point layer. According to the QGIS documentation, the childlayer has to have a foreign key. Unfortunately, my child layer has none. Is there a way to form the relation by ...
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