All Questions
Tagged with fields or fields-attributes
321 questions
10
votes
2
answers
7k
views
Creating memory layer and populate fields using PyQGIS
Seems like a basic operation using PyQGIS but can't see what I am missing. I want to create a memory layer with the exact same features and attributes from a shapefile. I have looked several posts ...
- 76.3k
8
votes
1
answer
9k
views
Is it possible to increase Output Field Name length beyond 10 characters?
When creating a new Column, the default value for the length of the name is 10. Using the Field Calculator via the Model Builder, I want to include the names of regional areas into the columns which ...
- 76.3k
7
votes
4
answers
4k
views
Fill with @row_number based on group field in QGIS 3
Is there a way to fill the table with a row number so that count will restart as new group (identified by a separate column) starts? As a result, "row number" column will restart the count ...
- 695
7
votes
3
answers
3k
views
Summing values in one field using PyQGIS
In QGIS 2.18 there is a shapefile with three fields accordingly
id
Type
Value
1
a
5
2
b
NULL
3
c
1
4
d
6
5
e
NULL
I want to get the total sum of all values in the field "Value". How ...
- 34k
7
votes
3
answers
896
views
Is it possible to have the attributes fields already filled from the previous object?
I need to create a lot of points with lots of attributes, but most of the fields are the same, so I don't want to edit all the fields all the time. Is there a "remember previous fields" function ...
- 71
6
votes
2
answers
3k
views
Choosing Shapefile attribute data type to use?
I am trying to figure out when to use (in the Data Type of SHAPEFILE PROPERTIES) - TEXT - SHORT-INTEG - LONG-INTEG - FLOAT AND DOUBLE.
I am using ArcView 9.3 and I know when it is all text or use ...
- 1,601
6
votes
3
answers
2k
views
Creating QgsFeature with default attributes using PyQGIS
I have a polygon layer loaded from PostGIS database. This layer has a default value for the first column. I can create a new feature set that attribute to some predefined value with:
newFeature = ...
- 268
5
votes
2
answers
5k
views
Select by attributes within the fiona Python module
Is it possible to select polygons from a shapefile based upon their attributes using the Fiona Python module? I can't seem to find anything in the docs, but it seems like a strange thing not to be ...
- 4,014
5
votes
1
answer
388
views
Creating new layer with all attributes inherited from original layer using PyQGIS
Let's assume there is a polygon layer called 'test2' with its attribute table, see the image below.
With the code below I am creating a new layer as centroids of original features
layer = iface....
- 34k
4
votes
3
answers
4k
views
Copy geometry from one layer onto attributes of another?
I have two polygon layers, A and B, that have the same features but totally different attributes. I want to use the attributes from layer A, but I want them to have the more accurate geometry from ...
- 1,314
3
votes
3
answers
5k
views
Adding many columns (to many layers) using QGIS?
The label toolbar uses fields in the attribute table of vector layers to fine tune labeling (Data defined labeling). That's the main reason i'm looking for that, but it may have more applications.
I'...
- 7,888
3
votes
2
answers
4k
views
Updating polygon areas in QGIS?
I'm using QGIS 2.6 and regularly update a shapefile layer to indicate felling progress. However, if I edit the nodes of a polygon, save the layer out then look at the Attributes table the area shown ...
- 199
3
votes
1
answer
5k
views
When aggregating points by polygons with sp::over function, how do I include attribute data from both the points and polygons? [duplicate]
Data: Zipped ea.ml1 shapefile can be found here, and the country outline can be downloaded here at the GADM site. I've been using the Ethiopia ESRI shapefile. Branch locations are here.
I have a ...
- 1,912
2
votes
1
answer
3k
views
Adding attribute list to combobox in QGIS plugin?
I am developing a simple plugin at the moment which contains 3 combo boxes:
comboBox_1
comboBox_2
comboBox_3
Combobox 1 & 2 lists the vector layers available, however I would like the 3rd ...
- 76.3k
2
votes
3
answers
6k
views
Changing field type with ArcPy?
What I need to do is change data type of a field of a table or feature class. If there are some data, then I need to transfer it, if its possible, if not possible then just set null for that data. I ...
- 2,425
1
vote
2
answers
570
views
Getting attribute data from one dataset to another
In the image below you can see two shapefiles: NYC building footprints (outlined), and underneath a PLUTO shapefile rendered with a categorized blue gradient using the "Floor Number" column. The ...
- 403
1
vote
1
answer
16k
views
Changing field formats in ArcGIS geodatabase? [duplicate]
I am working with data in an ArcGIS 10.1 geodatabase. I wanted to complete the simple task of taking a ten-digit ID field that is currently in String/Text format and create an identical field in Long/...
- 1,235
23
votes
8
answers
54k
views
Deleting fields using QGIS
When is the option to delete field in an attribute table enabled in QGIS?
I'm in editing mode and still am not able to delete a field.
- 5,618
17
votes
3
answers
20k
views
Changing position of columns in QGIS Attribute table
If I have an attribute table with columns A, B, C, and D, is it possible to move the columns to different positions, say: B, C, A, D?
When making a new column with the Field Calculator it would be ...
- 1,015
17
votes
3
answers
906
views
Sorting attribute table by hidden column in QGIS Print Composer
In a QGIS 2.18.20 attribute table I have some values with random numbers, but at the print composer I want to show them with order (clockwise). So I made a new integer column, and added numbers with ...
- 741
17
votes
5
answers
15k
views
Converting string field into date field in QGIS
In QGIS I have a layer with points which represent the fatal road accidents and the field "dates_14_D" contains their date but its type is string. I would like to convert this string field ...
- 792
16
votes
3
answers
13k
views
Exporting only certain columns to CSV file in ArcGIS for Desktop?
I've written a python script using arcpy which outputs a polygon feature class into a File Geodatabase. I have added a function to export the attributes to a separate CSV file. I am using the code ...
- 22k
15
votes
7
answers
32k
views
Changing field length using QGIS
I have a shapefile I made in QGIS 1.7.4. One of the fields is a String of length 80. I'd like to make the field accept longer stings, but I can't figure out how to change its length.
How do I do this?
- 1,123
14
votes
1
answer
10k
views
How to change attributes with QGIS Python?
I have this piece of code which I would like to use for inserting values into a column. It does not throw an error, the changes are not written to the source (shapefile).
from qgis.utils import iface
...
- 4,262
13
votes
2
answers
10k
views
AttributeError: 'QgsVectorLayer' object has no attribute 'fieldNameIndex'
When I try to calculate a new field with:
idx = layer.fieldNameIndex(attributeName)
I receive the following error:
AttributeError: 'QgsVectorLayer' object has no attribute 'fieldNameIndex'
What´s ...
- 446
13
votes
3
answers
4k
views
Setting default value in QGIS field
I would like to add in a layer's field a default value. I mean, every time a new feature is created, that field would be automatically filled with the default value.
In my case the default value would ...
- 3,768
12
votes
2
answers
21k
views
Updating text column of selected features in QGIS
Let's say I have a bunch of postcodes. After making a selection and having the records highlighted in the attribute table, how to update all of them and give them the same category?
In ArcGIS, after ...
- 2,350
11
votes
1
answer
10k
views
Applying Field Calculator with PyQGIS
I would like to use Field Calculator in PyQGIS to update the existing column based on certain conditions.
How can I do this?
- 607
11
votes
1
answer
914
views
Setting all the values in attribute field to the same value with PyQGIS
When I use "Update existing fields" in the Field Calculator in QGIS 3.16.0-Hannover, it takes only a second to change all the values in a attribute field to the same value. However when I ...
- 375
9
votes
2
answers
4k
views
Displaying multiple attributes in QGIS Composer legend
I have a polygon layer which has a number attribute and a text attribute.
When I make a legend in the composer, it automatically chooses the number to display while I would like to have both the ...
- 470
9
votes
3
answers
4k
views
Renaming field in attribute table via PyQGIS
How can I rename a field in PyQGIS?
I tried:
for field in layer.pendingFields():
if field.name() == 'old':
layer.startEditing()
oldname = field.name()
field.setName('new')...
- 155
9
votes
3
answers
14k
views
How to group by attributes and give unique categories in QGIS?
I have features and each of them has an attribute about what it is. In my case, I have points representing trees and each tree has its species name as an attribute.
I would like to group them by ...
- 1,053
8
votes
4
answers
2k
views
Adding unique ID for groups of items using Field calculator in QGIS
I have a set of string values in a shapefile's attribute column and want to assign a number to them in a way that each unique string gets an integer number, like this:
How do I do this using the ...
- 125
8
votes
2
answers
3k
views
Change default field properties for number format in ArcMap?
Anyone who has worked with numbers that have more than 14 digits has run into ArcMap's wonderful habit of converting any number of such length to e-notation. While changing this is a simple matter of ...
- 4,318
8
votes
2
answers
638
views
Clean up attributes
I want to clean up the attribute table of a road shapefile for all the entries in the fields.
For example: As seen below I have a road feature with a "Name", Name From and Name To in the attribute ...
8
votes
2
answers
2k
views
Finding the minimum value of different columns in QGIS
I'll try to calculate the minimum value of four different columns in my QGIS table like:
The min. value would be 1,50286 in the first row.
Is there any expression or tool to find the minimum value ...
- 183
7
votes
2
answers
622
views
Removing duplicates from field using ArcPy with ArcMap
I am using ArcPy with ArcMap.
I need to remove duplicates from a field named "Intersecti"
Here is my code. I used list..set. It's not removing any duplicates.
import arcpy
duplicates = &...
- 145
7
votes
4
answers
4k
views
Calculate polygon field based on neigboring polygon attribute
I have a vector shape with many different sized polygons each possessing an own class name (for instance "houses", "houses with offices", etc ...)
I want to assign a new field to ...
- 8,180
6
votes
5
answers
9k
views
Adding point to existing attribute record, rather than editing attributes of existing point?
I'm using ArcGIS 10 to create point data. Normally I would start an edit session, select point as a construction tool, click where I want a point to be, and then go in and edit the attributes.
Say I ...
- 61
6
votes
1
answer
2k
views
Defining fields and adding features to the output layer in a processing algorithm in QGIS
I have two input vector layers (one point and one line layer). I loop through every feature in the input-line-layer and calculate some things (with the help of the point layer).
What I am trying to do ...
- 725
6
votes
3
answers
1k
views
Wrapping heading of column of attribute table within QGIS Print Composer
The "wrap text on" function seems not to work for the heading of the columns, only for the rows.
I'm using QGIS 2.14.4
- 309
6
votes
3
answers
5k
views
How to collect data via WFS and Popup
I have a map with a WFS-Layer and I am able to add Polygons to my data stored in a PostGIS-database, served with GeoServer (OpenLayers, GeoServer 2.1.4, PostGIS 2.0 for PostgreSQL 9.1).)
How can I ...
- 329
5
votes
3
answers
734
views
Define a unique ID (serial number) based on values in a field
I'm trying to generate a unique serial number for a dataset I have, for example, something like this:
As shown, I would like to have a serial field, called SERIAL in this case, that increments based ...
5
votes
1
answer
755
views
QGIS Symbology - Display more symbols for each point depending on attribute numeric value
I have a point feature layer with some attributes. The numeric value of each attribute stands for the number of items of that attribute related to each point.
Is it possible in QGIS to display a ...
- 518
5
votes
1
answer
3k
views
Dissolve (merge) polygons QGIS based on attribute values only when are adjacent
I am a fairly new user of QGIS having a question regarding dissolve functionality.
I am working with the NUTS-2 shapefiles provided by EU, which I have imported in QGIS. I have created a new layer ...
- 71
5
votes
1
answer
3k
views
QGIS Not Importing ExtendedData from Self-Exported KML?
I've been scouring the internet for the past few hours, and I just can't seem to figure it out!
I am using QGIS 2.4.0-Chugiak.
Here are my simple steps:
1) I create a new ShapeFile (Type: Polygon) ...
- 53
5
votes
3
answers
459
views
Styling points based on letter in field in QGIS
I am trying to do different symbols for my data in QGIS the only different between my points is the letter 'W' or 'D'. I want that each point will get a different color or shape to vizualize that on ...
- 59
5
votes
3
answers
744
views
Changing field types so graduated symbols are available
I can't seem to make graduated symbols work. When I try to click on my column it doesn't show any options.
I think these is due to those columns being formatted as text and not number. Any ideas how ...
- 51
5
votes
2
answers
4k
views
How to delete empty fields from a Shapefile with QGIS or ogr2ogr?
I have a Shapefile with a lot of empty columns but many of them are empty. Using QGIS or ogr2ogr, how do I remove all attribute columns where everything is NULL?
- 3,050
5
votes
3
answers
3k
views
Deleting features with identical table attributes in QGIS
How do I delete features with identical table attributes in QGIS? Otherwise, is there a tool like the 'Delete Identical Tool' in ArcGIS?
For example, if I had 4 rows, and 3 columns, where I wanted to ...
- 465