All Questions
Tagged with fields or fields-attributes
321 questions
33
votes
3
answers
35k
views
Understanding "Join Attributes by Location" in QGIS
I wonder if there is somewhere an explanation for the parameters that can be set when running the Algorithm "Join Attributes by Location" in QGIS 2.18.
I had a look here:
Documentation QGIS Testing |...
- 3,440
17
votes
3
answers
28k
views
Changing value of attribute of QgsFeature using PyQGIS
I would like to update one attribute of a feature. However, I don't know to update it using the feature object. I have to use a data provider to update it.
layers = QgsMapLayerRegistry.instance()....
- 535
16
votes
3
answers
39k
views
Summing data from column in QGIS Attribute table
I'm working with population data, and I have an issue when it comes to knowing the sum of a population inside the attribute table.
In my attribute table, I'd like to add all the numbers in the red ...
- 1,042
8
votes
2
answers
14k
views
Spatially joining polygon fields onto point layer in QGIS
I have gridded depth points in CSV format that I'm trying to add other map data to, in additional columns. I've tried joining fields, hoping that I could link the shapefile data to the CSV, but when I ...
- 1,089
52
votes
9
answers
59k
views
Identifying duplicate attributes in field using QGIS
I have a point shapefile with thousands of points. It has an "ID" code field that is supposed to be unique. Every now and then the data entry clerk wrongly type the "ID" creating ...
- 523
47
votes
10
answers
114k
views
Determining the centroid of polygons in QGIS
I have a polygon vector and I want to quickly attain the centroid of this polygon for insertion in a text document. I am working with QGIS. I searched through other questions and although some are ...
- 771
29
votes
4
answers
92k
views
Merging/Dissolving polygons by Common Attribute Field in QGIS?
I have joined corresponding Local Enterprise Partnerships table data into a polygon shapefile containing UK Local Authorities.
How do I Dissolve or Merge the the Local Authorities polygons by ...
- 471
14
votes
2
answers
35k
views
Maximum length of text fields in shapefile and geodatabase formats?
The maximum text string for a field in a geodatabase is 320 characters.
The data I am importing has long character strings and it seems to be truncating when I convert into shapefile at the max ...
- 165
29
votes
4
answers
59k
views
Reading attribute values using PyQGIS
What is the way to get the information contained in the attribute table, say in column 2, row 2 using PyQGIS?
- 309
20
votes
3
answers
35k
views
Selecting features using expression with PyQGIS
How can I select features with PyQGIS using an expression?
I tried to use an QgsExpression but the select method doesn't take it:
exp = QgsExpression("'ogc_fid' = 482")
cLayer = canvas....
- 8,049
10
votes
3
answers
13k
views
Deleting column/field in PyQGIS
How to remove or delete column fields in a shapefile using PyQGIS?
- 871
16
votes
4
answers
45k
views
Changing data type in QGIS Attribute table
I have county data in which the "FIP"s (actually State "FIP"s and County "FIP"s combined). I have data imported as CSV with the same "FIP"s data titled '...
- 301
9
votes
2
answers
30k
views
Why can't I edit attribute table imported through 'text as layer'
I imported the coordinates from an Excel table. They show as single points as intended. Now I want to add columns to the attribute table, but I'm not able to edit it. I wanted to import the following ...
- 93
96
votes
5
answers
157k
views
Renaming attributes/fields in shapefile attribute table using QGIS
I would like to rename some fields in my attribute table:
Like rename "XRF_N3"in something else. It seems quite a easy issue but I don't find any information about how can I do that.
- 2,078
52
votes
5
answers
38k
views
Change style properties of several layers simultaneously?
I'm working on bulk data. I have a few hundred GeoTIFF images imported into a QGIS project, and I'd like to modify their layer properties - things like the no-data-value, transparency of certain pixel ...
- 641
8
votes
1
answer
3k
views
Adding calculated fields with PyQGIS
In the Memory provider described in PyQGIS Cookbook and in the question Creating new empty vector layer with PyQGIS I can see how to create a Vector Layer programmatically using standard fields (...
- 159
32
votes
8
answers
29k
views
Getting list of distinct values from shapefile field using QGIS
I have a shapefile whose features I can filter by specifying a where clause in the query dialogue. F.x. I have a field named "city_name" and by stating "city_name" = 'London' in ...
- 550
30
votes
5
answers
60k
views
Grouping and counting attribute data in QGIS
I want to group and count features with the same code attribute value.
I can classify the data and enable feature count in the layer list but I cannot get counts in the attribute table.
- 331
17
votes
3
answers
25k
views
How to split text attribute by characters in QGIS?
Is it possible to make a new column, for example named "Test" and store the first part of the column "Name" split by -?
See below how it should look like:
- 189
15
votes
4
answers
11k
views
Re-ordering fields permanently using ArcGIS Make Query Table tool?
In the Answer to Reordering fields (permanently) in file geodatabase using ArcGIS Desktop? it was stated that the Make Query Table tool could be used to re-order fields in tables and feature classes ...
- 65.4k
11
votes
3
answers
15k
views
Getting attributes of selected features using PyQGIS
Could anybody provide an example how to get the attributes of selected features?
I tried the following code in the Python Console : but I'm stuck at the point where I'd like to get the attributes:
...
- 261
22
votes
9
answers
73k
views
Changing Field Name in ArcGIS Desktop
How can I change the field names (not the alias) in ArcGIS 10.2?
I already found this page on ArcGIS support: "Renaming shapefile fields (Defense Mapping)" but there is is not "Defense ...
- 1,498
11
votes
1
answer
2k
views
Creating predefined values in field using PyQGIS
I would like to make programmatically (with Python) the same thing than we can do directly in QGIS when you create a list of values for a field.
I would like to create a new field and specify a list ...
- 597
10
votes
5
answers
26k
views
Changing fields order in QGIS
I have to draw several stuff and input the data, all the layers have the same data fields but some require 2\5 attributes to be filled.
Is there a way to change the order of those fields to be on top ...
- 509
9
votes
1
answer
23k
views
Summarizing column in QGIS field calculator?
I have data with a column containing a number value, and I want to divide the value of each feature by the total sum of all the values in the column (to get a percentage).
So I would like to know if ...
- 2,666
9
votes
5
answers
21k
views
Renaming field using ArcPy?
What I need to do:
rename a field name of a table/feature class
copy all values to the new field
So far I have done following code as @artwork21 suggests:
import sys
import traceback
import arcpy
...
- 2,425
6
votes
1
answer
368
views
Attribute subdomain in QField/QGIS
I have a point layer with the attribute/field:
kingdom
with a value map widget so I can choose the values: Tree or mammal.
And a second field:
Species (where I will register: Pine, Oak, Deer or Fox)...
- 77.7k
6
votes
2
answers
1k
views
Modifying width and precision of database using QGIS?
I have a database in txt format made of several columns of real numbers. Two column are integer, 17 are real (rounded to the first decimal) and 17 are real rounded to the second decimal.
If I import ...
- 179
2
votes
2
answers
3k
views
Building raster with multiple attributes based on 3 input rasters?
I am trying to make a new raster based on three input rasters which have the same cell size and the grids align perfectly.
I now want to construct a new raster, which for each cell, has three ...
- 351
1
vote
2
answers
4k
views
Summarizing data using ArcGIS Desktop?
I am relatively new to GIS and am facing some difficulties trying to summarize/pool data together.
I've attached the file to make it easier. FID_pc11_1 (Refers to postcode identifier) and count ...
- 11
24
votes
10
answers
14k
views
Sorting by multiple fields at same time in QGIS?
Is it possible to sort multiple fields at the same time in QGIS?
For example, I'd like to sort a table by state name, and then within each state, sort by county name.
This would be the same as ...
- 8,356
16
votes
3
answers
9k
views
Getting field names of layer using PyQGIS
How does one get a list of attributes/field names of a layer by means of PyQGIS 3?
If my layer has field names seen in the attribute table or properties. How can I use PyQGIS to give me a string list ...
- 1,073
12
votes
1
answer
8k
views
Writing vector layer to CSV file with geometry using PyQGIS?
I use Python try to write vector layer file to csv file with this code:
QgsVectorFileWriter.writeAsVectorFormat(mylayer, r'c:\temp\xyz.csv', "utf-8", None, "CSV")
It can export to xyz.csv but only ...
- 121
11
votes
4
answers
13k
views
Looking for QGIS equivalent of ArcGIS "Summarize" [duplicate]
In ArcMap, the user can create a table that groups the field values using summarize field tool (as shown below)
How can I create a table that summarizes field values in QGIS?
- 389
11
votes
3
answers
16k
views
Merge lines with the same 'name' attribute on QGIS?
I have a shapefile with a few thousand lines, each is a street segment. I'd like to merge all features with the same 'streetName' attribute into a single attribute. I only really care about the name ...
- 111
8
votes
4
answers
30k
views
Python Script to Add Fields to Feature Classes
I have to try to add a field called 'Name' to a bunch of different feature classes using python, and then access the name of the feature class to fill in the field. I have no idea how to even start ...
- 429
8
votes
1
answer
3k
views
Creating variable distance buffers in QGIS
I would like to create variable distance buffers for some points in QGIS 3.4.
I have seen in previous posts that there used to be a tool for this in older versions of QGIS, but that this tool wasn't ...
- 351
7
votes
1
answer
5k
views
How to style a vector layer in QGIS using hexadecimal color code stored in attribute?
I have a polygon shapefile storing hexadecimal color codes in a specific attribute.
gid | label | color
---------+-----------+------------
1 | Crops | #FF5F2C
2 | Forest ...
- 2,720
6
votes
2
answers
1k
views
Hiding column in attribute table by using PyQGIS
Is there a way to hide a column in the attribute table by using PyQGIS?
By hiding I do not mean hiding only the edit widget, I would like to hide the column completely.
It is possible to achieve that ...
- 93
6
votes
1
answer
11k
views
After performing table join all the fields are "NULL" in QGIS
Within QGIS, I joined .dbf table containing population data to a shapefile of Census tracts.
The join field is called "GISJOIN" in both the target table and the shapefile's table, and this ...
- 323
5
votes
2
answers
6k
views
Updating the attribute table of feature using PyQGIS
The following code updates the value of the field ("name") in the console and shows the result but the actual attribute table does not get updated. Can anybody suggest the error in the code?
...
5
votes
2
answers
3k
views
Converting double field to integer in database view so ArcMap query layer can use field as unique identifier
I have a field in a table that is a double data type, but the values are actually integers. The table is from third-party software, so I don't have control of the field data types.
I'm attempting to ...
- 1,272
3
votes
1
answer
9k
views
Exporting QGIS contour attributes in DXF file?
I have a .tiff data file that generates contours in QGIS. I save it as .dxf. The contours don't have any attributes or data. That's bad, because I want to make a 3D landscape in Revit using the ...
- 31
2
votes
1
answer
6k
views
Assigning field value based on location without join
I'm interested in updating a field in geodatabase feature classes based on their location in relation to another feature class in the geodatabase, but without having to perform a join (and therefore ...
- 220
34
votes
3
answers
20k
views
How to easily edit attribute data using Regular Expressions?
I am writing a tutorial for MSc students that uses QGIS.
One of the tasks requires the attribute data to be modified
(see pdf draft of tutorial here if interested ).
The question is how to get them ...
- 4,274
18
votes
2
answers
19k
views
Creating drop down list with values in QGIS
I want to show a drop down list in the feature attributes dialog.
I have three different building zones. The hot Wohnzon A, B residential zone and residential zone C. Now I have an attribute called ...
- 623
18
votes
4
answers
19k
views
Filter features based on their attributes using Python
How to get features by their attributes (similar to 'IQueryFilter' in ArcObjects) in QGIS using Python? Instead of getting all features and filter it manually, is there any option to use where clause ...
- 1,051
17
votes
2
answers
24k
views
Summing values in field using QGIS
Using QGIS 1.8, I've got a shapefile with an integer field called "AREA" and I'd like to sum the values which are in this shapefile.
Does anybody know how to?
- 171
14
votes
2
answers
17k
views
Getting field names in PyQGIS
I am trying to change an plugin from QGIS 1.8 to 2.0.
In the 1.8 version I create a table of the field names like this:
layer = vlayer
provider = layer.dataProvider()
feat = QGSFeatrue()
allAttrs = ...
- 2,918
12
votes
1
answer
6k
views
KeyError: '-1' when adding field and calculating expression with PyQGIS
I want to use PyQGIS to add a new field and calculate the values for each feature. Similar to the Field Calculator option.
My 'Field Calculator' expression is for example: y(start_point($geometry))
...
- 243