Questions tagged [many-to-many]
n:m. One, or more, rows in one table is linked (or related) to one, or more, rows in another table using a "key" column
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Managing PostGIS many-to-many relationships between several tables with different geometry types from QGIS
I have this data set stored in a PostGIS (16+3.4) database:
Each category of items being stored in its own table:
CREATE TABLE public.rock
(
id INT PRIMARY KEY GENERATED ALWAYS AS IDENTITY,
...
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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 ...
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How to handle many to many relationship?
I'm dealing with land development, where a land could have multiple investments and the other way around.
What I've got:
A shapfile with all land informations, each labels an unique id.
LAND_ID
AREA
...
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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 ...
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Many to many relationship class with ArcGIS Desktop using only two table
In database discussions, for creating many to many relationship class we must create a third table to relate two other tables.
However, in ArcGIS for creating many to many relationship class we just ...
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Aggregating result of many to many join of points closest to line in QGIS
I have a layer of points and a second layer of lines. The goal is to know for each line, how many and which points (by "ID") are closest to that line, to then export this information for ...
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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 ...
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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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Creating child entries in QGIS form with Spatialite many-to-many relationship
I am trying to reproduce the example from Introducing many-to-many (N-M) relations using Spatialite. Creating the tables and the relations works fine, but when I try to create a child element in a ...
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Linking new feature violates foreign check constraint in PostgreSQL database when working in QGIS3
I have set up a spatial database in PostgreSQL in which I have some data/tables that need to be linked by M to N relations. For those occasions I have two tables that contains geometry and a pivot ...
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Many-to-many joins in QGIS
Just want to know if there is a tool to do a many-to-many join in QGIS?
I have X number of polygons that I want to join with a CSV table which contains Y number of entries. Essentially I need to have ...
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Many-to-many relationship and QGIS Forms
I have a PostgreSQL/PostGIS database with a base table (Pois_points) and two subtables which constitute a many-to-many relationship with the base table, as you can see on the picture below (click on ...
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Setting up and displaying many-to-many relationships with CartoDB
I have to display many-to-many relationships between offices and sub-offices for a client. Each office manages many sub-offices, each sub-office can be managed by many offices. The client is ...
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Using the Make Query Table for Querying a Many-to-Many relationship
I have two tables that I have connected via an attributed relationship class of the cardinality Many-to-Many. One is a table of water body (rivers) features and the other is a series of pollutants ...
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Using many-to-many join in ArcMap
I'm working in ArcMap 10 and can move around in R, though am not an expert.
I have a shp file and an xlsx file.
The shp file is 20,221 rows and includes a field GID (grid ID) which is not unique ...
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