The selection of data from a database based on some criteria.

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5
votes
3answers
151 views

How to select specific rows of polygons from a grid in QGIS?

I have a polygon layer. I would like to select every second row of the polygons but not manually. Is there an expression to select every second row as seen on the picture with Select by expression in ...
3
votes
2answers
59 views

How to select the most populated neighbourhood of each town in the country using QGIS?

I have data from a national census with population for each neighbourhood, grouped by municipality and town, in the country. I want to select the most populated neighbourhood of each town (there's a ...
2
votes
1answer
23 views

Using ArcGIS ModelBuilder in to Select By Attributes?

I have a file showing for each disaster, which provinces were affected. The number of provinces affected varies and their names or associated code varies as well. Example, if a flood in 2000 ...
0
votes
1answer
34 views

How to select congruent polygons in PostGIS?

Title says it all. What is the best way to select congruent polygons in PostGIS? CREATE TABLE polygon_a ( gid serial NOT NULL, geom geometry(Polygon, your_SRID), CONSTRAINT polygon_a_pkey PRIMARY KEY ...
1
vote
0answers
29 views

Selecting certain area of polygon according to size in ArcMap?

I have a set of polygons with a certain size (3500 sq meters each for examples). I only need 3000 sq meters of every polygon. Is there an automatic or semi-automatic way to create sub-polygons out of ...
0
votes
2answers
46 views

Selecting from selection based on attribute table in ArcGIS for Desktop?

I selected polygons which are less than 313 m2 and from that selection I need to select the ones that are completely within some other polygon. So, both selections are on the same shapefile. I ...
2
votes
1answer
54 views

Select features empty OpenLayers 3?

I created in OL3 selector elements new.ol.interacion.Select () on a WFS layer, and when I try to take these features returns an empty array. My intention is to create a json with the selection check ...
3
votes
0answers
64 views

Select by expression doesn't work - QGIS [closed]

I want to make a "selection by expression", as shown on the screenshot. I choose the FIELD and the VALUE from the side panel, but it's selecting 0 rows (there are actually more than 100...). I ...
3
votes
1answer
135 views

Set selection color transparent and border color red in QGis using python

I have a layer with different informations. I want to change the selected polygon color to "Transparent". I am able to achieve that using: iface.mapCanvas().setSelectionColor( QColor("Transparent") ) ...
1
vote
1answer
45 views

Why is select features button not working in ArcGIS 10.3?

Every time i opened a mxd file (in ArcGis 10.3) the default of most of the layersis in "Not Selectable". I search a way to change the default in the table of content ,so all the layers will be always ...
0
votes
1answer
33 views

ArcGIS Select largest N rows in group

I have feature class (Name: V1) in personal geodatabase with columns: Height [float] and Id [int] representing group number I need to do SQL query that will select eight highest 'Height' values in ...
1
vote
1answer
35 views

Selecting Minimum values from in_memory dataset!

I am trying to select the minimum value from a data set being stored in the in_memory workspace. This prevents me from using sub-queries. I'm hoping that someone has found a work around for this issue ...
1
vote
1answer
40 views

How to select attributes by unicode field value?

I have an attribute table in QGIS 2.10 with a string field (myfield) and when I want to make a selection based on the unique values of this field I get no selection at all. >idxmyfield = ...
1
vote
1answer
59 views

Deleting selected features with ArcPy?

I am having trouble deleting the features I have selected using 'arcpy.SelectLayerByLocation_management' tool. To use the select layer by location tool, you much pass in a .lyr file. My script ...
1
vote
2answers
81 views

Select feature one by one not working in pyQGIS?

I have used following code for selecting the features one by one. but when i run the script it is just selecting last feature and zoom it. I want to select each feature and zoom it. def ...
4
votes
1answer
82 views

Select feature one by one and save it as image

I have used following code for selecting the features and save it as image. layer = self.iface.activeLayer(); layer.setSelectedFeatures([]) count =layer.featureCount() lstChalta = [] lstFeatures = ...
0
votes
0answers
18 views

Looping all features of cursor onto SQL Server feature class?

It might be me but I've been experiencing something weird. (I actually tried what suggested in this thread Arcpy MakeFeatureLayer won't loop with no luck) What I'm trying to accomplish is to use ...
2
votes
2answers
98 views

Selecting Polygons that have certain raster data within them

I am using a raster layer with either 1 or 0 in each cell. On top of this layer, I have a European countries shape file. The countries that contain a '1 cell' in the raster beneath are the Countries I ...
0
votes
1answer
46 views

Arc Map 10.1 Identify tool

I'm trying to identify features from multiple layers. For example, I have many locations around a river (within a 100 m buffer) which I would like to identify, but instead of having to draw rectangles ...
1
vote
2answers
55 views

List Attribute values selected by location

I would like to get a list of road features that intersect every county in a state and output it as CSV or Excel. Ex: county A intersect the Road Names a b c county B intersect the Road Names e ...
0
votes
0answers
20 views

How Show shp Selected [duplicate]

I need help with code to know if a SHP a MXD this selected or not. I have the following code which only shows me all shp'sy layers are in the layer , I need a list if there is a selecionado shp, ...
1
vote
1answer
20 views

QGIS 2.8 Change Colour of Selected features [duplicate]

How can I change the colour of the selected features in QGIS. The light yellow is not easy to see.
2
votes
2answers
94 views

QGIS Select double feature by attributes

There is this point shapefile in QGIS (2.12). There is one column with the street name and one with the housenumber. Is it possible to select all features that have the same street name and ...
3
votes
2answers
65 views

Copy/convert selection into filter/query builder of QGIS?

Can anyone tell me if it is possible (and how) to convert or copy a selection on a layer (that has not been created through "select by expression", but instead by irregular selections from a canvas, ...
0
votes
0answers
10 views

Using predefined variables in whereclause? [duplicate]

Can't seem to figure out how to use variables for an SQL whereclause in python. e.g. want to select_analysis(layer, "new sel", field = attribute) with field and attribute being predefined by user ...
2
votes
1answer
52 views

Attribute Table Window loses highlighted selection after Addin is Opened

I'm so new to GIS that this question might seem dumb to a lot of GIS Developers. I have taken over a project that is an AddIn for an ArcGIS Desktop app. C# VS 2010 project. I can get the Selected ...
3
votes
1answer
45 views

In ArcGIS 10.x, how do I select features of a point shapefile whose z values are above or below the elevations in a DEM?

I have a multi-point shapefile representing earthquake hypocenters (containing depth values) and I have a DEM raster representing an underground surface (the top of the PreCambrian basement). I want ...
2
votes
0answers
19 views

Is there a way to apply the “Select features by rectangle\polygon…” function on multiple layers simultaneously?

I have put a map together using openstreemap data that is intended to be used as a base for different projects. However due to the amount of information (number of layers) the loading time is rather ...
1
vote
0answers
34 views

Is there a way to select polygons by geometry (right angle)? [closed]

Is there a way to select polygons by geometry? I need to find a way to detect all the polygons that have a right angle, but I can't find a tool that can do that. I'm using QGIS 2.10.1 and ArcGIS ...
2
votes
2answers
133 views

Selecting features within polygon from another layer using R or Python?

For Selecting features within polygon from another layer using QGIS? the solution was to: use the "Vector->Research tools->Select by Location" However, I would like to know how to do the same ...
1
vote
2answers
71 views

Variable Expression In ArcGIS

I am creating many models doing many tasks. Basically, the first model will join 2 tables and the steps are as follow: make table view for each table, then add join for, then it will copy the rows for ...
1
vote
2answers
77 views

Switch selection of specific polygon

I'm using ArcGIS 10 desktop version. I have a number of polygons, let's say 300, in a layer. Each polygon contains information of schools, ranging from 100 to 250 points, in a separate point layer. ...
1
vote
2answers
191 views

How to pass only selected features in python toolbox

I have a feature class in a file geodatabase. I want to select features from the feature class and export their attribute to an excel sheet. I need a python tool in ArcGIS which does this. My problem ...
1
vote
1answer
178 views

Creating buffer around WFS features to ease their selection in OpenLayers 2?

I'm using a WFS SelectFeature from OpenLayers 2 to show a Popup containing the features' attributes from line layers and point layers (from GeoServer). This works fine, but I would like to create a ...
1
vote
1answer
81 views

Communicate relation between two table

At this time, I'm able to create a relation (1:M) between two table or geometries. After, I user Identify tool to exploit the relation. It is only possible to use this feature when your Identify tool ...
0
votes
0answers
40 views

how I can get raster calculator select files with similar names?

The idea is to select raster files with parts of similar name, for example: Filenames (in between many others raster with other names, but in the same folder): 28feb11evs 28feb11evv 28feb11pr ...
0
votes
3answers
104 views

Show selected features on all zoom levels in ArcMap?

Is there a way to display selected features no matter the scale level in ArcMap 10.3? When I select by attribute and then zoom to selection I often just get a blank map since the layer is set not to ...
1
vote
2answers
67 views

Selecting nearest 300 buildings (polygons/centroids) from list of points using ArcGIS for Desktop?

I have been trying to look for an easy/quick way to select a certain amount of polygons (layer 1) from a 90 points shapefile (layer 2). The idea is to identify the nearest 300 buildings from each of ...
2
votes
1answer
65 views

QGIS 2.8+: How can layer.selectedFeatures() return an empty list while layer.selectedFeatureCount() returns the correct number of selected features?

I noticed some changes since qgis 2.8 but can't find any information about it. Let's say I have a very simple point layer loaded in QGIS, from a spatialite table. From this layer I select some points ...
1
vote
1answer
165 views

Label only selected feature using QGIS?

Is it possible to make an expression that labels only the selected feature in QGIS? I tried it with this expression in the label tab: attribute( $currentfeature, 'LAENGE' ) But it labels all and not ...
1
vote
2answers
56 views

Select points located within Multi Ring Buffer

I have two point datasets, 1 showing the location of road accidents, the other showing the location of traffic intersections. I have created a Multi Ring Buffer at 25m intervals around the traffic ...
2
votes
1answer
62 views

How can I do a subquery inside a subquery in PostGIS?

I need to add a subquery to a working function. Instead of select * from table, I'd like to select * from (select * from table where height>1500) as sub, something that works in other functions I ...
1
vote
1answer
224 views

How to SELECT all points within a GeoJSON polygon in PostGIS

I have a GeoJSON polygon, and a table with lots of points. I want to SELECT all points that are within an arbitrary GeoJSON polygon. How can I do that with PostGIS SQL?
0
votes
0answers
77 views

Select polygon feature(s) in ArcMap and pass this selection into Python Addin

Does anyone has an Pyhton example to select polygon feature (or features) in ArcMap and pass this selection into a Python Addin? The selection made by mouse will be better.
2
votes
1answer
92 views

Joining data of two different datasets from varying distances and integrating into one dataset in ArcGIS

I have a pointfile of some 200 electrical boxes throughout the county. While the electrical boxes are "mapped", they are done so by using township range section data, so there actual location is not ...
1
vote
2answers
160 views

How to select features containing specific text string using an expression in QGIS

I need to style a survey parcel polygon shapefile, based on whether the polygon is a mineral claim or not. Unfortunately, the only information on whether a polygon is a mineral claim or not is ...
1
vote
1answer
72 views

Working w/ Shapefiles Containing 50,000 to 300,000 Features

I work daily with shapefiles that are quite large in number of features using ArcGIS. Sometimes I am able to perform operations (joins, selections, exports, etc) on these shapefiles (though they do ...
0
votes
1answer
127 views

Python Script to Select records based on user input

I am running Arc 10.3 in a versioned environment. I am attempting to write a simple code that will select service records coming from Oracle CRM to a separate feature class containing only records ...
0
votes
1answer
95 views

Counting Features to Calculate Field Value

Generally, I am trying to find the # of features in one shapefile within 1000 feet of EACH feature in a second shapefile - and then populate a field in the first shapefile with that #. More ...
1
vote
0answers
28 views

Is order of selection in Spatial Data important (attribute, location, graphic)?

When dealing with spatial data in a GIS system, does it matter which way you select the information if you're using all 3 - attribute location and graphical selection? In my experience it seems to not ...