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

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17
votes
4answers
8k 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
3answers
5k 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 ...
12
votes
2answers
8k 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 ...
8
votes
2answers
1k views

Trouble with graduated symbols after joining shapefile with csv file

I have successfully joined data from a csv file to a shapefile in QGIS but for some reason I am having trouble symbolizing my data. I want to use a graduated symbology however this option is not ...
8
votes
1answer
2k 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 ...
7
votes
5answers
8k 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 ...
7
votes
4answers
2k views

How to close multipart polyline gaps in ArcMap

I have a multiple multipart contour lines that originally came from CAD drawing. I converted these into a polyline shapefile in ArcGIS. The issue I have is with gap in each contour lines that are ...
7
votes
5answers
565 views

How to programatically identify the “Joined Field” in ArcMap?

Is it possible to programmatically identify the Join Field that is being used to Table Join two datasets together in ArcMap? I am currently using ArcGIS 10.0, SP5 and would prefer an ArcPy solution, ...
6
votes
2answers
3k views

Joining tables without losing original field names in ArcGIS for Desktop?

I'm wondering if there is any method to preserve the original field names in ArcGIS when I join csv. tables to a Shapefile. I ask, because sometimes I join tables with 10, 20 or even more columns ...
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 ...
6
votes
1answer
86 views

Is there maximum number of .DBFs that can be joined using ModelBuilder?

Is there a maximum number of .DBFs that can be joined using the Join Tool in ModelBuilder? I tried joining 480 .DBFs but results generated only 250 fields in the input table. Is this a glitch? I am ...
6
votes
2answers
2k 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 ...
6
votes
2answers
172 views

How to enumerate join values with ArcGIS?

I have two shape files (e.g. postal code areas and cities) which I want to join based on an id that both shape files have in common (the id would be the city name in this example). Joining the two ...
6
votes
1answer
786 views

Can Spatial Joins be used to perform One-to-Many Closest joins?

My situation appears rather simple, but it has given me headaches more than once already. I have a set of points and a set of polylines. I would like to use a spatial join to join the attributes of ...
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
3answers
2k views

FME: Join attributes in text file with attributes in SHAPE file

I have a SHAPE file with points and different attributes - one attribute MyID. I also have a plain text file with several attributes - each in a separated column: MyID MyValue 1 A 2 B 3 C ...
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 ...
5
votes
3answers
1k 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: ...
5
votes
1answer
568 views

How to use a search cursor on a joined table in ArcMap?

I'm struggling to get a search cursor to work on a joined table view. I've used search cursors before, but never on data that has been joined. Arcpy keeps saying that some of my joined fields don't ...
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 ...
5
votes
1answer
2k views

Creating a spatial “Many to one” join

I'm trying to create what I call a "many to one" join. I don't know if that would be the correct term or not. I have a table that has unique account numbers for mobile homes (i.e. - M1007970) per ...
5
votes
2answers
1k 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
1answer
49 views

Is it possible to have a 1:n join which takes the min, max, or average value?

I need to join the attributes of a shapefile with the one contained in a .dbf (or .txt) file. I currently use the "join" in the properties menu, but I have a problem. In the shapefile I have one ...
5
votes
1answer
393 views

How do I avoid text field truncation when saving a table join?

Using QGIS I've joined tabular text data (all in fields of less than 255 characters) to a shapefile via a CSV file. All looks good in the joined table but when I save to a new shapefile to make the ...
5
votes
1answer
676 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 ...
5
votes
1answer
212 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 ...
5
votes
3answers
914 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 ...
4
votes
7answers
20k 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
4k views

ArcGIS - Create a join based on multiple fields

I have two feature classes in a File Geodatabase that I would like to join based on multiple fields. I've searched this site and Google and all I have come up with was to use the Make Query Table ...
4
votes
1answer
126 views

Most efficient method to join multiple fields in ArcGIS

I have as set of shapefiles with approximately 300000 polygons each, as well as corresponding point shapefiles and tables with approximately the same number of row (equal or less rows than the ...
4
votes
2answers
391 views

Spatial join - many to one

I'm trying to do a spatial join that takes the attributes of multiple polygons and applies them to a single polygon in another layer. The data is currently in a geodatabase, but can be exported to shp ...
4
votes
1answer
566 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 ...
4
votes
1answer
132 views

QGIS 2.2 - possible to do a JOINS from the Action list?

I have a set of layers that need to be joined (Layer Properties > Joins) to one specific layer. The reason for this is that I will be updating and adding new layers into my project and would like a ...
4
votes
1answer
588 views

Spatial Join in PostGIS according to Line Attribute

I am in the process of building a data warehouse in PostGIS, that will store the length of the road network of a country (Lines) per Administrative Area (i.e. Province or State, referred to as AA ...
4
votes
2answers
548 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 ...
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 ...
4
votes
1answer
158 views

Find max and min values from a table based on two fields

I have a geodatabase table with the following fields: County_Name, State_Name, Date_Time, Customers Example Alameda, CA, 8/1/2014 12AM, 6 Alameda, CA, 8/1/2014 1AM, 1 Alameda, CA, 8/1/2014 2AM, ...
4
votes
1answer
168 views

How do “join field” and “target field” work?

New user. This should be simple, but I can't figure out how to perform this basic join in QGIS. (It works in Cartographica.) My shapefile (IL_BNDY_County_Py) has two fields/columns in its attribute ...
4
votes
3answers
2k views

How to join two tables using date, time, lat and lon as common field?

I am sorry if the question is elementary but I did not find any clear discussion or guide to understand how to run a query in postgresql. So that a pointer to another website would be also useful. ...
4
votes
1answer
274 views

How to join data from NHGIS to make choropleth maps in R/ggplot2?

I have downloaded shapefiles of county/state boundaries and census data keyed to those shapefiles from the NHGIS. Both the shapefiles and the census data have a GISJOIN column to be used for merging ...
4
votes
1answer
493 views

How to join fields which must still be created in ArcGIS Model Builder?

I am in the process of creating a generic model in ArcGIS Model Builder. At one point in my model, I have to do a join between an existing layer (entry parameter) and a table issued from the "Zonal ...
4
votes
1answer
244 views

Join a table to a parcel layer and get duplicate parcels, reflecting individual leases

I have a table of 3,000+ lease files that I'm trying to join to our parcel layer. Each parcel has 4+ leases associated with it, and I need each to be represented by an actual polygon. When I do a ...
4
votes
1answer
147 views

QGIS 2.0.1 linking table issue, MSSQL 2008 database

I'm trying to link tables in QGIS 2.0.1 and MSSQL 2008 database. I can link them but when I try to open the attribute table QGIS throws an error and shuts down creating a *.dmp file. I saw that ...
3
votes
2answers
326 views

Join a CSV file to shapefile using gdal/ogr?

I have a shapefile with several attributes, for example YEAR, COUNTY, and AREA. I also have a CSV file with more fields that I want in the shapefile, such as POPULATION. Both the shapefile and the CSV ...
3
votes
3answers
1k views

Copy dbf data into a shapefile in Arcpy

Basically it's to perform a one-to-many join in a python script, from a dbf to a shapefile. I saw (Greg Krakow's method) using QGIS, but I can't use it (I'm working on it, but QGIS is not yet ...
3
votes
4answers
173 views

How to assign geometry to records in a table that contain an ID of a geometry point?

We are looking to map out 'incidents' at schools, but the incident table, which contains a few thousand records, only has a school number (plus the incident data). The table format is an Excel ...
3
votes
2answers
388 views

Arcgis not seeing my column header to join tables

I am trying to join a data table to the attribute table of a shapefile. I have done all the necessary steps to makes sure it works: removed spaces, not use numbers in column headers, remove illegal ...
3
votes
1answer
108 views

Field calculator uses wrong fields when working with joined data

I am having an issue in qgis table joins. i have a joined a csv file to a sqlite database and common id is used for join. the join is displays correctly in attribute table. the attributes in sqlite ...
3
votes
1answer
110 views

Join is deleting fields in arcpy

I'm working on a script to automate the conversion of CAD .dwgs of rooms to feature classes, I'm nearing completion and am now working on the second portion of the script (I've seperated it into two ...
3
votes
1answer
624 views

Joining table to shapefile with pyQGIS

Joining shapefiles is a relatively straightforward proess in QGIS using 'add vector join' in the layer properties menu. I can add a csv file as a vector layer, as well as a shapefile, and join the two ...