The process of connecting two or more datasets based on a common attribute or spatial location.

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7
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1answer
1k views

How to perform a spatial join of point and polygon layers in PostGIS?

I have a point dataset representing households that I want to associate with a parcel layer (i.e. assign its parcel_id). With ArcMap, I could spatially join the polygons to the points and specify that ...
1
vote
1answer
482 views

Enhance performance of a join query for mapnik using postgis

I use mapnik to render map with datasources from a postgis database. One query is a join on two table, one with a geometry (a polygon) and the other one with some fields I want to use for rendering. ...
1
vote
0answers
49 views

GeoJoin with ArcGIS Services [closed]

Has anyone seen any ways to dynamically join data in services. E.g. I've already exposed County boundaries in a MapService, now I want to let users join their relative data to this service for their ...
2
votes
3answers
714 views

How to join a WFS layer to a stand-alone table in OpenLayers

I'm a complete novice at OpenLayers, and am checking whether the following is possible. I envisage a dataset of polygons in GeoServer, being served as a WFS layer into OpenLayers. The polygons won't ...
1
vote
1answer
659 views

How to join an external table to a set of polygons, and symbolize on the joined values, in a web map?

Say I have a table showing a number of statistics - for example, various gun crime by US State measures. I also have a dataset of state boundaries. How can I join the table to the features in a web ...
6
votes
1answer
2k views

Spatial distance join between polygon and points using R?

I'm figuring out how to do a Intersection (Spatial Join) between point and polygons from shapefiles. My idea is to get the closest points and those points that match completely inside the polygons. In ...
5
votes
1answer
657 views

How to merge linestrings that don't touch based on common name?

I had a table of road line strings that contained duplicate road names with different geoms for different line segments. I extracted the duplicates to another table. I now want to join these segments ...
4
votes
1answer
505 views

ArcObjects joins and non-persistent fields after joining to multiple tables

I have inherited a truly awful and very large ArcObjects project that was originally written in VB and then ported to C#. Apparently the source code I have been given is not the latest version and I ...
1
vote
2answers
607 views

Join/Relate in ArcGIS 9.3.1 ArcEditor through a python script - is it possible?

I'm working on a ArcGIS 9.3.1 ArcEditor and I want to write a python script that will do a Join or Relate. Problem is, that join table\join field are restricted to ARCINFO (higher license), and relate ...
6
votes
1answer
1k views

Join attributes of point and line layer by location (closest distance) in QGIS

My problem is the following: i have a line shp (target layer) and a point shp (join layer). the second one (point layer) holds an attribute which i want to join with a line layer based on closest ...
5
votes
1answer
203 views

Reading an Existing Join

Confused again. I was finally able to run ArcCatalog and create a join in my map document (I will do the deed programmatically eventually) but I was interested in how a join looked once it was ...
3
votes
1answer
119 views

Deep merge data from multiple layers

Let me explain what I mean by "Deep Merge" and what I am trying to do. Suppose that I have 3 layers (Layer1, Layer2 and Layer3) with the same field names (field_a, field_b and field_c). For any ...
4
votes
7answers
17k views

Having problems with joining an excel table to a shapefile in ArcMap

I have a shapefile of lower layer super output areas (LSOA) for England and Wales and I have a spreadsheet of the indices of deprivation for each of the LSOA's in England. I want to join the ...
4
votes
2answers
495 views

How do I correctly perform a spatial join between lines that travel along each other in ArcGIS

I have 2 layers, one representing streets, and one representing pipes. The pipe layer has a street field that I want it to be automatically filled (I want the pipe to show the street that it's on) I ...
11
votes
2answers
7k views

How to join external tables with a shapefile's attribute table in QGIS?

I need to join a .csv table into an attribute table of a shapefile. I wanted to do this with QGIS and i don't seem to find anyway of doing it. I know that the mmqgis plugin does it, but my shapefile ...
5
votes
5answers
1k views

Spatial Join on two point featureclasses produces empty output featureclass

I have two point featureclasses that intersect each other. They are in the same projection and dataframe. The issue is, when I perform a Spatial Join the output point featureclass is empty. The file ...
6
votes
2answers
1k views

Difference between two layers in PostGIS

What is the right way to calculate the difference between two layers? I tried to use the following approach: SELECT ST_Difference(river.geom, lakes.geom) FROM river LEFT JOIN lakes ON ...
0
votes
0answers
230 views

How to Query Parks in GeoNames and Combine it With a Polygon Layer?

I run a hiking site and would like to get parks where you can at least have a nice walk. That means they should not be playgrounds, stadiums, and probably be bigger than 3 square city blocks at least. ...
12
votes
3answers
4k views

How to join attributes from nearest point in QGIS?

I have two layers with points, call them A and B, each with different attributes. For each point in A I want to join all the attributes from the nearest point in B. Ideally this would also include ...
5
votes
3answers
943 views

How do I remove a join (between a standalone table and a feature layer) with ArcObjects?

I already know how to do a table join with ArcObjects, via the IDisplayTable, IMemoryRelationshipClassFactory etc. interfaces. Here are some links to resources that have example code for this: ...
7
votes
5answers
7k views

How to join multiple records to single feature?

apologies for what I'm guessing is a really easy problem to solve. GIS user, not programmer here. I'm trying to create a join/relate in QGIS where I have a shapefile of buildings and to that I would ...
2
votes
1answer
279 views

How to join averaged precipitation values to each municipality

I have precipitation data that I would like to average over each municipal unit in a boundary layer. First, how do I average the rainfall spatially by each administrative unit? Second, the rainfall ...
3
votes
1answer
691 views

Help with joining a large dbf file to shape file

My overall objective is to create a timeline animation depicting when a person is working in a particular region. The .dbf table consists of over 6000 record entries of shift data, including date ...
5
votes
2answers
941 views

Creating polygons from a one to many relationship of points

I have a set of polygons that are in a one to many relationship with points. The polygons are administrative boundaries and the points have information on companies and percentage of ownership . I ...
5
votes
2answers
4k views

Trouble creating a query table

I need to join one feature class and one table. This is a one to multiple join, therefore, my only option seems to be by creating a query table. My problem is that the fields I want to join do not ...
15
votes
4answers
7k views

Join non-spatial CSV to spatial data in QGIS

I have a csv which has postcode data in a field, but it is non-spatial e.g. no Easting and Northing. I have a shapefile with postcode in a field and some additional data. I want to join the csv with ...
4
votes
2answers
3k views

One-To-Many Table Relate Viewed Through ArcGIS Server

I want to create a Table Relate with a one-to-many relationship between a layer and a non-spatial table based on a common field. My question is, if I publish this data to ArcGIS Server, will an ...
5
votes
3answers
901 views

SDE views not showing values in joined table

I created an SDE view between a point feature class and a table (stored in SDE) - the join is done on a text field called RFRNC. I changed the view so that it is now a LEFT OUTER JOIN in line with ...
2
votes
2answers
460 views

Join Issue with Attributes Table

I am trying to Join a Mineral Database (excel) into my Attributes table. Once I do and check the Attributes, it shows up as "NULL". What is causing that, what am I not doing? Can anyone offer ...