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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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 ...
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 ...
28
votes
2answers
35k views

Joining polygons in R

I am wondering how to join spatial polygons using R code? I'm working with census data where certain areas change over time and I wish to join the polygons and the corresponding data and simply ...
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 ...
15
votes
7answers
43k views

Joining data from Excel to attribute table in QGIS without creating duplicates?

I have an attribute table with two empty fields in QGIS. I want to import an excel database to fill my empty fields in QGIS. My excel file matches the columns in my QGIS attribute table. I am able ...
15
votes
3answers
7k views

How to symbolize features with NULL values in graduated symbology?

I have a polygon feature dataset, and an attribute from a different table that I join (one-to-one) within QGIS in order to symbolise the attributes as a choropleth map. However, not all polygon fields ...
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 ...
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 ...
13
votes
1answer
4k 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 ...
12
votes
4answers
9k 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 ...
11
votes
2answers
5k 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 ...
11
votes
3answers
11k 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 ...
11
votes
5answers
6k views

After joining shapefile with CSV file graduated symbols option unavailable in QGIS?

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 ...
10
votes
2answers
693 views

Using wildcards for column headers in QGIS Field Calculator?

I know you can use wildcards for fields like so (in the Field Calculator): case when "column" ILIKE '%example%' then 1 else 0 end Can you do something similar for the column headers themselves? 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 ...
10
votes
1answer
13k 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 ...
9
votes
7answers
59k views

Joining Excel table to 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 ...
9
votes
2answers
11k views

One-to-many joins on a feature class to a table

I am using ArcMap 10.2.2 with an Advanced license. I have used ArcMap for other basic analyses, but am fairly new to the program and have only basic coding skills, with no SQL experience outside of ...
9
votes
2answers
5k views

One-to-many join in QGIS [duplicate]

I am looking for a possibility to make a one-to-many table-join in QGIS. I have a shapefile with postal codes and would like to join them with survey results (more than one). In other words, there ...
9
votes
5answers
2k views

Programatically identifying 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, ...
8
votes
2answers
13k views

Creating join based on multiple fields using ArcGIS Desktop?

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 ...
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(...
8
votes
2answers
5k views

How to join a table to a shapefile with non-matching IDs and names (similar strings)?

I'm having an annoying problem that I'm trying to find an automated solution for. The shorthand version is that I have a shapefile and a table of created data for regions within countries. The created ...
8
votes
2answers
9k views

Table join with .csv file results in null fields after join

Similar to questions already asked about .dbf files, I'm attempting to join .csv files to a .gdb or shapefile coverage in QGIS. The tables as added to QGIS prior to the join look fine, but after the ...
7
votes
3answers
7k views

Spatial join versus classical join [closed]

What are the main differences between a spatial join and a classical database join such as an equi (inner) join?
7
votes
1answer
97 views

Join shapefile and csv when identification uses two or more attributes

I have a shapefile and a csv file that I want to join. The csv file has: MSA identifiers County identifiers within MSA (so, across MSAs the county_id is not unique) a series of attributes (each ...
7
votes
2answers
497 views

In QGIS is it possible to apply an expression to a join

I am trying to join by 2 text fields and there is a lot of mismatch due to CaSe and space issues... can it be run so that it's lower("field1")=lower("field2") I otherwise have to create a new field ...
7
votes
4answers
8k 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
1answer
259 views

Select by Location and Join the Attributes of Two Line layers

I want to import the name of streets from OSM shapefile layer to another line layer based on neighborhood distance. The distances between two layers (line layers) are variable between 0 to 10 meter. ...
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: "...
6
votes
1answer
117 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
4k views

Keep the same field headers after joining a table to a shapefile in QGIS

I noticed that after joining a table to a shapefile the headers of each fields in the table used for the join are changed by QGIS and they are attributed to a different name. For instance, I had a ...
6
votes
1answer
1k 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 ...
6
votes
3answers
4k views

FME: Join attributes in text file with attributes in shapefile

I have a shapefile 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 ...
6
votes
1answer
3k 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 ...
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 ...
6
votes
2answers
8k views

Join / merge lines that touch and intersect in QGIS

I have a large dataset consisting of lines/polylines where I would like to join/merge the lines that touch / intersect. Each line has an individual ID and there are no common attributes I can use for ...
6
votes
1answer
2k views

Is there are way to import non-geo JSON files into QGIS?

Here is a json file containing various attributes relating to countries. However, it does not contain any geographic data. http://bost.ocks.org/mike/nations/nations.json I would like to join these ...
6
votes
2answers
566 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
4k 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 ...
6
votes
1answer
862 views

Joining Google Docs table to feature class at ArcGIS Online to use in Operations Dashboard?

I am using ArcGIS operation Dashboard. I get the Data Source from excel file that i have published using google docs as a dynamically data source. I need to join the excel table to hosted feature ...
6
votes
1answer
898 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 ...
6
votes
1answer
1k 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
854 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
4k views

Why do layers with different CRS overlap fine but cannot be merged by location?

Perhaps someone could clear this up for me? I have a shapefile with the CRS Selected CRS (EPSG:29902, TM65 / Irish Grid) I also have a number of XY points which take the CRS, Selected CRS (EPSG:4326, ...
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 ...
5
votes
1answer
296 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 ...
5
votes
1answer
2k 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 ...
5
votes
1answer
991 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 ...
5
votes
1answer
67 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 ...