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Questions tagged [null]

NULL is a value for an attribute value that contains no data. Sometimes not allowed due to 'not null constraints' or slt.

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I can't update any attribute values in PyQGIS

I've been using PyQGIS for a few of weeks. I'd write a script which shows all earthshakes responding to given parameters, so I wrote this code: from PyQt5.QtGui import * from PyQt5.QtCore import ...
ytreka's user avatar
  • 11
1 vote
0 answers
61 views

Remove all null values from attribute table and move all the other values to the left

I use ArcGIS Pro and have over 50 shapefiles. I used the Union tool to merge all the Features in one map including all the attributes. Now I have like 10.000 Features with way too many columns. On the ...
ThomasHaarlem's user avatar
0 votes
2 answers
67 views

reduceRegion works but reduceRegions returns null values for all reducer

When using ee.reduceRegions() I try to estimate the mean values of copernicus landcover values within all features in a feature collection I get 'null' as a result for all reducers I have tried (mean,...
David Christianson's user avatar
3 votes
1 answer
107 views

Missing values (NULL) handling in QGIS Statistics Panel

The handy Statistics Panel in QGIS 3.34.3-Prizren (accessible from the summation button) does not seem to recognize NULL values. I have a layer with about 10% NULL values but the Statistics Panel ...
john coleman's user avatar
1 vote
1 answer
59 views

Setting a Boolean field to be empty

I have a layer with a Boolean field called bool. I can set the field value to NULL, e.g. using the Field Calculator. When printed via Python, the values are correctly shown as None: >>> layer ...
bugmenot123's user avatar
  • 10.9k
0 votes
1 answer
128 views

ArcGIS Pro 3.1.2 change only blank selected cells in attribute table

I am using ArcGIS Pro 3.1.2. Is it possible to change only the null values cell in a selected dataset? I could have export the selected features as a new shapefile. Select the null values and replace ...
GIS Noh's user avatar
  • 321
2 votes
0 answers
56 views

Handling Nulls with QgsVectorLayer.getFeatures() and GeoDataFrame.from_features()

I am trying to convert selected features in a QgsVectorLayer to a GeoDataFrame. The input layer contains values including nulls across multiple floating, integer or string columns. For Example: When ...
cratcliff's user avatar
  • 156
3 votes
2 answers
216 views

QGIS expressions: creating an array based on integer fields returns 0 for field value NULL

Problem I use QGIS expressions (tested in QGIS 3.32.3 Lima and 3.34.0 Prizren on Win 10) to create an array based on attribute fields like array("field1,"field2"). I have fields of type ...
Babel's user avatar
  • 73.2k
2 votes
2 answers
248 views

Writing GeoDataFrame to GeoJSON without Null values in GeoPandas

I have a GeoPandas GeoDataFrame: geometry col0 col1 col2 col3 0 POINT (0.00000 3.00000) A A A NaN 1 POINT (1.00000 4.00000) B B NaN NaN 2 POINT (2.00000 5....
zabop's user avatar
  • 2,224
3 votes
1 answer
92 views

Remove columns with NULL values from QGIS print layout attribute table

I have an attribute table in my QGIS print layout that only includes features within the map extent. I want that table to only show columns that have non-NULL values for that feature set, i.e. if the ...
JackP's user avatar
  • 323
2 votes
1 answer
56 views

Allowing null outputs when mapping over FeatureCollection in Google Earth Engine

I have code working that extracts the area of forest loss from the Hansen Global Forest Change dataset for each available year and attaches it to the properties of a mapped FeatureCollection. This ...
jamierob's user avatar
  • 1,559
0 votes
0 answers
72 views

Why gdal_calc.py returns 0 (Zeros) instead of NaN in the output?

Why this gdal command returns 0 (zeros) instead of NaN in the outfile? gdal_calc.py -A aa.tif --outfile="out.tif" --type=Float64 --NoDataValue=nan --co="COMPRESS=DEFLATE" --format ...
jurajb's user avatar
  • 1,214
4 votes
1 answer
117 views

Deleting NULL geometries and duplicate nodes from table using PostGIS

I run the command to delete null geometry from a table: delete from table where geom is null And delete duplicate nodes by running the command: update table set geom = ST_Multi(ST_Simplify(geom,0)); ...
Paul P's user avatar
  • 113
3 votes
2 answers
155 views

Deleting contents of all entries in field in QGIS Attribute table

In QGIS, how can you delete all of the entries in a field in an attribute table? If you go to a particular entry in a field, you can delete that entry, but how can you delete all of the entries in the ...
Mark Polczynski's user avatar
0 votes
0 answers
31 views

Gstat outputs NULL when using variogram() function

I am trying to do a kriging interpolation on a fake data set to familiarize myself with gstat. This code has worked before on a larger df but for some reason when I try to make the variogram, the ...
Alaska's user avatar
  • 1
1 vote
1 answer
152 views

Prompt User in ArcGIS Pro Attribute Rules

In Attribute Assistant I have some prompts for the user to enter a value. Sometimes these fields do not have value and the field can be null. Attribute Rules don't have a prompt methodology. I am ...
Mary Ann Reyes's user avatar
0 votes
0 answers
55 views

Polygon on scratch or shapefile area returns null in QGIS & EPSG3857

Just got started with QGIS (the software) today and I'm getting Null for a hand-drawn polygon, even for a circle shape. Here is what I've done: Installed QuickMapServices plugin Installed GeoCoding ...
marciokoko's user avatar
2 votes
0 answers
122 views

Raster Calculator in QGIS returns -3.4e10^38 when saved

I'm using the raster calculator with the following formula: "myraster"@1-100 Now if I choose the option save as tiff file the resulting raster consists of cells with value -3.4e10^38 (...
vince's user avatar
  • 17
12 votes
1 answer
669 views

Concatenating labels in QGIS

I am trying to display labels for polygons in a dataset. Each polygon has about 5 different fields that I want to display. Depending on the polygon, there may be NULL values in the field(s) that I am ...
JackP's user avatar
  • 323
1 vote
0 answers
63 views

How to remove fields from insert or updates in QGIS

In QGIS 3.22 using a Microsoft SQL Server database I would like inserts or updates to ignore several columns. The reason being that some columns have values generated by the database. Currently when ...
Philip Whitten's user avatar
3 votes
0 answers
198 views

QField Geotagged Photos with NULL direction field

I have some geotagged photos taken in QField on an Android device. Whenever I import these photos into QGIS using the "Import Geotagged Photos" tool, the "direction" field is NULL, ...
nalacour's user avatar
0 votes
1 answer
211 views

Using ee.Reducer on monthly time series with missing data

I am trying to generate a value of mean MODIS LST for each month in a time series for a feature collection, as well as an overall timeseries minimum and maximum LST for each month of the year. When I ...
Hydro_data's user avatar
0 votes
1 answer
233 views

QGIS 3.24.1 - in QuickOSM, how to import raw OSM into GeoPackage and select which tags to import?

With overpass-turbo, I made a query and exported a raw OSM file. In QGIS 3.24.1, I import this OSM file into GeoPackage using the OSM File menu in QuickOSM plugin. It works but it imports all tags and ...
Vincenty's user avatar
3 votes
1 answer
755 views

In FME: how to handle NULL values in numeric expressions as 0 using the attribute manager

i stumbled across the following challenge in FME: how to deal with NULL values if you want to perform a calculation for a new attribute. For example, I want to sum up values (could be any other kind ...
Merlin's user avatar
  • 353
1 vote
0 answers
750 views

NULL values after merging layers with ArcGIS Pro ModelBuilder

in ArcGIS Pro I have two point layers, "Output" and "Output_2". Using the "Near" tool, I examine which points are close to each other, select some from "Output" ...
DMK's user avatar
  • 33
0 votes
1 answer
187 views

Make a loop to fill null pixels of an image with other images

I am new at Google Earth Engine and I want to fill null pixels of an image collection with pixels of complete images. In my case I want to make that in a loop, in which one the first image of a list ...
David Cerezo's user avatar
0 votes
1 answer
96 views

Surfer Null Island data issue

I'm trying to troubleshoot why my data is going to Null Island. I'm using Surfer for the first time. I have a .csv of several dozen points collected in WGS84, UTM Zone 16N. I've verified that the ...
redleg_64's user avatar
1 vote
0 answers
223 views

Use -unsetDefault to remove NOT NULL constraints with ogr/gdal

I have a feature class in a gdb that I wanted to export to a gpkg using ogr2ogr. This feature class has some null values that I want to retain and by default, there is a Not Nullable constraint when ...
gwydion93's user avatar
  • 1,913
0 votes
1 answer
378 views

Create a geopackage file with integer attribute containing NULL values in GeoPandas

I've been asked to produce a geopackage file in a specified format where one attribute is specified to be int64 nullable, and my case includes NULL values. Trying in GeoPandas, my problem is that I ...
jarveliu's user avatar
1 vote
1 answer
635 views

Problem with IS NULL condition in GeoServer CSS style

I have a style that divide features in PostGIS layer to four categories based on atributte Z_KAT. In the fourth category I want to specify that Z_KAT is equal to '04' OR null value. Condition for text ...
TomyPoty's user avatar
4 votes
2 answers
326 views

Can a Geopackage Boolean field contain a NULL value? [closed]

QGIS 3.24.3. When I create a Geopackage Boolean field, the default display is the word false, displayed in italics. Likewise, if I calculate the Boolean field = NULL, they also display as an italic ...
Stu Smith's user avatar
  • 8,192
0 votes
1 answer
955 views

QGIS Raster Convert Negative Values to NULL

I have a DEM layer in QGIS and want to replace all cells with negative values to the value "NULL". How can I achieve this please?
Fitch's user avatar
  • 49
2 votes
1 answer
1k views

QGIS reads blank cells as "nan" instead of "NULL"

I use QGIS to visualise my data but I use R when I have to do many treatments on my attribute tables. (package terra) But when I write vector data with R, the Na's appear in QGIS attribute table as &...
Anthony's user avatar
  • 133
1 vote
1 answer
1k views

Date coming through as NULL when data type is set to "date" in csv/t

If I set the data type to date(DD-MM-YYYY) in the CSVt file the date comes through but as a String/text. But I really need it to be date type. My CSV field looks like this: NAME,DATE,TIME,SPECIES ...
Stoat's user avatar
  • 21
5 votes
2 answers
842 views

Python error in Update Cursor for ArcGIS: " 'int' object has no attribute 'type' "

I am fairly new to python and am trying to make a script that looks through an ArcGIS feature class and updates <null> values to 'tbd' or 99999 based on the field type (string, double/integer). ...
Gsci's user avatar
  • 71
5 votes
3 answers
270 views

Nullifying the whole row in data attribute table at once in QGIS

I have a situation as you can see below: and I would like to have one row cleared completely at once. Is it possible?
Geographos's user avatar
  • 4,049
2 votes
2 answers
457 views

Set NULL values to 0 in specific columns using PyQGIS

I have over 20 fields and I wish to set the NULL values in the final eight fields to 0. I want to be able to do this both with the field calculator and with the PyQGIS console. At the moment neither ...
helpwithphysics's user avatar
2 votes
1 answer
370 views

Why $x and $y gives some results NULL and other correct values for one point layer? (on one only table of attributes)

I created a point layer starting on lines (with revised geometries) and then tried to obtained the coordinates of several point layers created from the same procedure and also joined all the point ...
Matías's user avatar
  • 23
0 votes
0 answers
37 views

Nested for: I execute changeAttributeValue in the outer loop, print it and is still NULL... but inner loop works kind of fine?

A bit hard to explain, untill now my script is: I have a for, where: if an "Analized" attribute is NULL, I will change it to "Parent",store a "Join Value" attribute in a ...
javir Ib's user avatar
3 votes
2 answers
496 views

Getting not NULL values from three columns in one column in QGIS

As you can see, I have three columns with the important features for me (a, b, c, d, e, f) - no matter of size. I want to copy them into new column "name". The problem is when I try to copy ...
Amla's user avatar
  • 33
6 votes
2 answers
676 views

QGIS constraint not null depending on another field value

Does anyone know it is possible in QGIS to add a constraint to a field not to be null, only when another field has a certain value. For example I have a field A that can be with value 'foo' or 'bar' ...
Jérémie's user avatar
  • 103
0 votes
0 answers
180 views

Zonal Statistics results are Null in QGIS

I am relatively new to QGIS and I am having issues with Zonal Statistics. I keep receiving NULL as my results for the median. I am trying to create a map displaying the median temperature for each ...
Sally's user avatar
  • 9
2 votes
0 answers
209 views

QGIS raster calculator syntax to turn `nodata` values to other values

In QGIS raster calculator, how is the syntax to refer to nodata values? Lets say I have a raster and want to generate a binary output raster with data -> 1 and nodata -> 0. There is an easy way ...
Babel's user avatar
  • 73.2k
0 votes
1 answer
857 views

Replacing zero with no data in CSV file using ArcPy cursor

I have a CSV file with zero as some of the attribute values. Trying to use cursors and replace all zeros with no data or blank values. I am able to replace any numbers. But not able to update with ...
Sara's user avatar
  • 1
2 votes
1 answer
84 views

How to avoid default_value in field with ArcPy cursor (e.g. row[i]=None)

Some field in field_list has default_value=1 After executing the following code, such field is filled with the value «1», but normal fields are filled «Null». How could I avoid this for the field (...
Александр Коробкин's user avatar
0 votes
1 answer
67 views

SearchCursor from source TEXT field set as <Null> being interpreted as ' ' (writing to DOUBLE)

I am Curious about the behaviour of the SearchCursor on a server Database feature class. the data for some of the the fields I want to read is set as TEXT, with some of those fields values set as <...
Dami Barnes's user avatar
6 votes
2 answers
2k views

Concatenate multiple fields where some contain null values (QGIS)

In QGIS 3.18. In a shapefile attribute table, I need to create a field that concatenates several other fields with a comma delimiter. Some of those fields are NULL. Currently my approach has been ...
pete's user avatar
  • 1,101
0 votes
0 answers
63 views

GRASS QGIS v.vect.stats returns NULL for all polygons

I'm running v.vect.stats from Grass using the processing toolbox in QGIS to take an average of a point layer attribute for points falling within a set of polygons. After running the algorithm a ...
pbreach's user avatar
  • 133
3 votes
1 answer
308 views

Filtering NULL values in date field in QGIS [duplicate]

In QGIS 3.16.9 I would like to find all the locations that have a NULL value. It is for a date field in the field services Drains dataset. I have been searching the use of NULL around various forums. ...
Matt Sully's user avatar
1 vote
1 answer
235 views

Using .CSV file as an external dictionary, but can't find a way to reference/make a key for Null in order to assign it a value using ArcPy

I am using ArcGIS Desktop: ArcMap 10.8.1 and using Python 2.7.18. I have a script that uses a .CSV file as an external dictionary (opposed to creating a dictionary within the script) but I cannot find ...
fortheloveofgis's user avatar