Questions tagged [many-to-many]

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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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 ...
5
votes
2answers
1k views

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 ...
4
votes
1answer
4k views

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 ...
4
votes
1answer
452 views

Accessing “many to many” relationship class using ArcGIS Identify?

I am trying to create a many to many relationship class in ArcGIS 10.0. When Identifying the features though, I don´t see the associated table values. Here is the Class schema: Destination Table ...
4
votes
1answer
103 views

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 ...
4
votes
0answers
120 views

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 ...
4
votes
0answers
150 views

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 ...
3
votes
1answer
2k views

How to add data to relationship table in ArcGIS 10.1 database design?

I have created 2 tables HORSE and VENDOR and a relationship table VENDOR_HORSE With the foreign key in Horse being the Primary key in VENDOR (VendorID) and the foreign key in VENDOR being the primary ...
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0answers
45 views

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 ...
1
vote
0answers
260 views

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 ...
0
votes
0answers
25 views

Image analysis over multiple image collection

I'm trying to calculate GPP with multiple MODIS and other observed data for 20 years. The MODIS GPP in GEE is not right in my AOI. I've calculated the variables (same number of bands) and stacked with ...