Questions tagged [attribute-joins]

The process of connecting two or more datasets based on common attribute values. For spatial joins there is a separate tag.

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13
votes
2answers
16k 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
3k 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 ...
8
votes
2answers
3k 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 ST_Intersects(...
29
votes
5answers
18k views

Joining 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 ...
6
votes
6answers
2k 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: "...
25
votes
6answers
31k views

Joining multiple records to single feature using QGIS?

I'm trying to create a join/relate in QGIS where I have a shapefile of buildings and to that I would like to join a non-spatial table (.csv) containing people who work in each building. So I have ...
4
votes
1answer
333 views

Joining averaged raster values to each feature using ArcGIS for Desktop?

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
1k views

Help with joining a large DBF file to shapefile

My overall objective is to create a time line 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 ...
6
votes
2answers
2k views

Creating polygons from one to many relationship of points using QGIS or PostGIS?

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 ...
10
votes
2answers
3k views

Detecting Join programmatically using ArcPy?

I have some Python code that is launched from within an ArcMap project. Any joins that the user may have created in the project must be removed in order for my code to run. Unfortunately, the code ...
40
votes
4answers
36k views

Joining non-spatial CSV file to spatial data (shapefile) using QGIS?

I have a CSV file 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 ...
13
votes
1answer
3k views

Why do simple joins on small datasets slow down ArcMap so badly?

ArcGIS 9.3.1, ArcInfo. I have some small file geodatabase and SDE featureclasses (few thousand records each, 50 columns) that I am doing attribute joins on. After the joins, drawing of the map is ...
5
votes
3answers
1k 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
512 views

Join Issue with Attribute Table

I am trying to use the tool to make the join a Mineral Database (excel) with my attribute table. When I check the attribute table, it shows up as "NULL". Why does it causing that and what did I do ...