Questions tagged [unique-id]
Unique identifier is any identifier which is guaranteed to be unique among all identifiers used for those objects and for a specific purpose.
83
questions
1
vote
1
answer
133
views
Assigning unique ID to new points in QGIS
I want to add a new field to my feature attribute table. In this field, I want to generate a random ID (just a number, like 1, 2, 3, etc.) for every new and existing point I create on the map.
This is ...
- 91
3
votes
1
answer
79
views
Clipping buffers by Unique ID
I am doing my thesis on worldwide river discharge data availability.
I need to know how to cut buffers with their corresponding vector/polygon that have an unique ID.
I have stations worldwide with ...
- 31
0
votes
0
answers
13
views
I am using BioOracle data and reducing it to 1 point per cell but when I try to covert to a sf grid, I end up having issues
I am using multiple BioOracle layers as geotiff files and reducing it to 1 point per cell, but when I try to convert to an SF grid, I end up having issues. I keep receiving an error stating:
Error in ...
3
votes
1
answer
129
views
Fetching only ids of features with QgsFeatureRequest in PyQGIS
Using a QgsFeatureRequest by default will fetch all attributes (including geometry) of the features. I can use .setFlags(QgsFeatureRequest.NoGeometry) to not fetch the geometry, and ....
- 47
1
vote
2
answers
130
views
Removing points outside of polygon but keeping points with the same feature ID using PyQGIS
I have a polygon layer and a point layer. The point layer has specific features in its table such as an ID called "fwg_type". There can be several points with the same "fw_type".
I ...
- 11
3
votes
1
answer
126
views
Calculating new id with suffix for another id field that has duplicates in QGIS
I have a linear dataset that has a unique "ID" for every row, but many of the linear features needed to be segmented. After segmenting, there are some rows that were split into two, three, ...
- 138
0
votes
0
answers
59
views
QGIS Distance to nearest hub wrong point selection for distance calulation
I'm using the graphical modeler in QGIS 3.28.8 to automatically calculate distances of two lines between points, see the picture.
To do this, I'm using Distance to nearest hub (line to hub) and an ...
- 1
5
votes
1
answer
2k
views
Adding automatic numbering of the "id" field in QGIS
I'm working on QGIS 3.22.6 and I would like to find a way for my "id" column to be automatically numbered as geometry is added.
I am currently using maximum("id") + 1 within the '...
- 97
3
votes
2
answers
166
views
Adding parcel number to site when there are many sites in QGIS
I have a PostgreSQL table with 7000 records relating to grounds maintenance.
Each site has a site reference number and I want to assign a sequential parcel number within each site starting at 1 to n.
...
- 397
2
votes
1
answer
333
views
Get a group from layerTreeRoot using its unique id using PyQGIS
I am having trouble when loading some layers in QGIS. I want to place them in specific groups and sub-groups but a problem occurs when multiple groups and sub-groups have the same name. The only way I ...
1
vote
2
answers
72
views
Calculating field with consecutive number based on another field in QGIS
In QGIS I am working on a streets layer, on the attribute table I have these fields:
"CVE_VIAL" is an ID of the street and each street could be divided into several sections, each of these ...
6
votes
2
answers
343
views
Assigning IDs in regular point layer using QGIS
I have a uniform point layer generated by using the Regular Points process. My goal is to connect (draw a line to join) a certain number of points in this points layer in a snake pattern.
My current ...
- 157
0
votes
1
answer
53
views
Retrieving fieldname of vectorlayer's unique id using PyQGIS
The name of vectorlayer's unique-id fieldname can be technically any string ("ID","FID","OID","id_0", etc) and its position can be technically anywhere. So ...
- 1,158
5
votes
2
answers
391
views
Generating unique positive integers as id with ogr2ogr
I create an example GeoJSON:
import shapely.wkt
import geopandas as gpd
s0 = shapely.wkt.loads("POINT(0 0)")
s1 = shapely.wkt.loads("POINT(1 1)")
gdf = gpd.GeoDataFrame({'geometry'...
- 2,662
3
votes
1
answer
174
views
Numbering points that are contained in polygons in QGIS
In QGIS 3.16.8-Hannover I have a layer with polygons and I have a layer with points. Each polygon contains a certain number of points, I would like to assign a number to each point in sequential order ...
1
vote
1
answer
208
views
Calculating distance from point to line, depending on unique ID using QGIS
I have four points of interest for each plot, a line representing the segment that faces the road and the plots themselves for representation purposes (all of them share in common an unique "id&...
- 55
0
votes
1
answer
114
views
Integer representation of textual value (as unique ID for query layer)
I have an Oracle 18c non-spatial table that has textual IDs as the unique ID:
The table doesn't have a ObjectID or numeric ID. I'm not able to add new columns to the table.
The table isn't registered ...
- 1,222
4
votes
2
answers
2k
views
Unique id forever QGIS
I need to create a unique id when adding an object to a shapefile (point, line, polygon).
I read a lot of things about that, but stay sceptic when using it.
I presume static field can not be envisaged ...
- 630
3
votes
2
answers
779
views
Adding unique ID for consecutive groups using Field calculator in QGIS
I found a similar question on this site and the answer suggested:
array_find(
array_distinct(
array_agg("PortCluster_ID")
),
"PortCluster_ID"
) + 1
...
3
votes
1
answer
658
views
QGIS graphical modeler and FID
I created a model to import different shape files coming from ARCMAP, to load them into my geopackage of my project.
The model does different things: Delete attribute (OBJECTID, SHAPE_LENGTH and ...
- 1,688
4
votes
1
answer
277
views
Generating list of IDs from intersecting lines
I have a line ('line 1' for example) that sits on top of another set of lines in a separate layer ('line 2' we shall name it). 'Line 2' has within it a field for IDs. What I need is to populate a ...
- 101
2
votes
1
answer
2k
views
Appending field from one layer into a different layer in QGIS
In QGIS, I have one layer (called 'All data shapefile') which is a shapefile with my entire set of data, and another layer (called 'Y_data') that is also a shape file with a subset of 'All data ...
- 141
1
vote
1
answer
269
views
How to attribute each datapoint to a specific buffer ID
I have many datapoints within 57 buffers in GIS (see picture for an example of a couple of the. buffers with datapoint inside). I need to be able to analyze each buffer separately, and therefore need ...
- 141
3
votes
1
answer
401
views
Creating unique ID for features that are within polygons with unique IDs
I need to create and "ID" for items within a polygon that also takes into account the name of the polygon that the item is within, so what I need is something along the lines of: poly_X_Item ...
- 101
5
votes
3
answers
1k
views
Giving grid cells unique ID of numbers and letters by rows and columns
In QGIS 3.16 I have a grid made up of c.900 squares and I want to give each square in the grid an individual name.
I want rows to be numbers and columns to have letters so when they meet that is our ...
- 51
5
votes
1
answer
165
views
Unique attribute value across multiple layers
We are in the process of cleaning up our asset database which contains day 20 of layers generally in file geodatabase format and includes point, line and polygon types and some non spatial tables.
Is ...
- 1,357
10
votes
1
answer
16k
views
Unique constraint failed error when saving GeoPackage in QGIS
In QGIS, when using Processing tools, the temporary output layer in many cases cannot be saved as Geopackage. This happens for example when using "Explode lines" or "Multipart to Single ...
- 73.8k
0
votes
0
answers
189
views
Count duplicates in a field for sequential unique ID
I am trying to create a unique ID for my street feature class. (My unique ID starts with first 3 letters of the Street Name, 2 letters of the Street type, and 3 letters of the City Name Abbreviated.)
...
5
votes
1
answer
117
views
Creating IDs for middle point of line
I have line layer as shown here:
I created middle point of line by using the below query in virtual layer.
SELECT ST_StartPoint(ST_Line_Substring(geometry, 0.5, 1))
FROM "TR_ROAD copy"
The ...
- 865
6
votes
1
answer
632
views
Creating Unique IDs of points in order from west to east
I have a dataset with over 1000s points. I am wondering if I am able to give each point a unique ID starting from west to east.
I am using ArcMap 10.6. Is there a way to do this in ArcMap?
user173865
0
votes
0
answers
123
views
Linking Excel spreadsheet property records to cadastral basemap in QGIS using ERF numbers as the unique identifier
How does one link land parcel polygons in QGIS to an Excel spreadsheet of property records, using ERF numbers as the unique identifiers?
2
votes
3
answers
447
views
Expression for assigning ID by grouping and ordering polygons in QGIS
To solve a problem (details see here) I am looking for an expression in QGIS (3.16) that creates a new field and should achieve this:
On a polygon layer, it should group together all polygons that ...
- 73.8k
0
votes
0
answers
52
views
Autopopulating field based on values from different field
When we ID our utilities (water pipes, storm manholes, etc.) we use ID's derived from a grid system. Our city is divided into grids that have a letter and number attached. "J14", "J15&...
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
2
votes
0
answers
99
views
Filling column with values at certain condition in QGIS
I have blocks of the road network and these blocks are divided every 200m.
I want to name them based on the ID_Sufix number. For example, if the stretch road ID is 10001 and this contains 26 small ...
- 405
1
vote
0
answers
562
views
Generating UUID(unique ID) at joining points
I have road network (lines) and points (Address) . With the help of closestSegmentWithContext function, I join points to nearest lines in QGIS. Is there a way to to generate a unique ID at every ...
- 865
8
votes
3
answers
2k
views
Adding consecutive unique ID starting from 1 for each distinct set of values
I need to add a unique ID (using $ID or @row_number) but the problem is that I need to start from 1 to "...n" considering identical values from other field, then, when there is a different ...
- 300
5
votes
2
answers
6k
views
Adding unique ID automatically in Field calculator as counter in QGIS 3
I tried a lot by Field Calculator but it gives me NULL as you show in table and another try it gives me value 1 in all rows.
Most of examples, on internet they are explaining old version and I have ...
- 111
7
votes
3
answers
3k
views
Creating GRID with customized labels in QGIS
I would like to know how can I create a GRID layer with customized labels as you can see in the image below:
I have searched this topic here:
Creating indexed vector grid in QGIS?
QGIS Python ...
- 980
2
votes
0
answers
204
views
Snap GPS coordinates to closest line, get line ID, generate and execute URL
I have a web map in Portal that has a sidewalk line layer.
Using Portal, I plan to collect sidewalk deficiencies using GPS (on a Microsoft Surface/Windows 10 device).
I would like to add the ...
- 1,222
1
vote
0
answers
73
views
Unexpected query layer results: Why does unioning with DUAL fix it?
Simple Query:
I have a query that connects to a table in a work order management database (Oracle 12c; non-GDB).
select
wo.wonum
from
maximo.workorder wo
The query returns 428 records in ...
- 1,222
1
vote
1
answer
45
views
Splitting lines: Options for managing IDs and related records
I have roads in a feature class (Oracle 10.3 geodatabase).
Roads are split into separate lines where they intersect. This is an established business rule that cannot be changed.
Each road has ...
- 1,222
4
votes
1
answer
7k
views
Joining attributes by field value not working
I cannot figure out why this join is failing when using the Join attribute be field value tool in QGIS 3.6.
Please see my image below which highlights the two layers attribute table and the criteria ...
- 3,272
3
votes
1
answer
480
views
How to export a unique ID field of a geopackage
When I am converting my geopackage file in shapefile, the unique ID field is not exported. I could duplicate it before exportation, but I wanted to know if it could be done in one step, in order not ...
0
votes
1
answer
72
views
New ID in QGIS not duplicated [closed]
I work mainly with ArcGIS in backoffice, but use QGIS for some field data maintenance, the challenge is that:
The info worked in office has about 4.5M records, but for maintenance purposes, we create ...
- 29
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
1
vote
0
answers
138
views
Make Query Layer - field not available as unique identifier when using NVL [duplicate]
I need to create a spatial view with Make Query Layer. My query includes outer joins, so I must combine every table's ID field to create a unique identifier. Since there might not always be a child ...
- 9,684
0
votes
1
answer
140
views
Field Calculator: Prefixed, padded IDs from a number field
Using the Field Calculator, I want to create prefixed, padded IDs from an existing number field. By "padded", I mean I want the IDs to have a specific number of characters, regardless of how many ...
- 1,222
0
votes
3
answers
2k
views
Sequential IDs with field calculator: Pad a prefixed field to specific length
I have an ID field that is a text datatype. The IDs in the field have a prefix, and are padded with zeros to always be a specific length. Examples:
INSP000098
INSP000099
INSP000100
INSP000101
I ...
- 1,222
1
vote
1
answer
720
views
Find records with highest value based on unique ID
I'm trying to find a way to return all records that have the highest value in a field for each set of unique IDs. The attached table shows what I'm trying to achieve. The highlighted records would be ...
- 283