23.1.18. Vector table¶

Add autoincremental field
Add field to attributes table
Add unique value index field
Add X/Y fields to layer
Advanced Python field calculator
Drop field(s)
Explode HStore Field
Extract binary field
Feature filter
Field calculator
Refactor fields
Text to float

23.1.18.1. Add autoincremental field ¶

Adds a new integer field to a vector layer, with a sequential value for each feature.

This field can be used as a unique ID for features in the layer. The new attribute is not added to the input layer but a new layer is generated instead.

The initial starting value for the incremental series can be specified. Optionally, the incremental series can be based on grouping fields and a sort order for features can also be specified.

23.1.18.1.1. Parameters¶

Label	Имя	Тип	Описание
Input layer	`INPUT`	[vector: any]	The input vector layer.
Field name	`FIELD_NAME`	[string] Default: „AUTO“	Name of the field with autoincremental values
Start values at Optional	`START`	[number] Default: 0	Choose the initial number of the incremental count
Group values by Optional	`GROUP_FIELDS`	[tablefield: any] [list]	Select grouping field(s): instead of a single count run for the whole layer, a separate count is processed for each value returned by the combination of these fields.
Sort expression Optional	`SORT_EXPRESSION`	[expression]	Use an expression to sort the features in the layer either globally or if set, based on group fields.
Sort ascending	`SORT_ASCENDING`	[boolean] Default: True	When a `sort expression` is set, use this option to control the order in which features are assigned values.
Sort nulls first	`SORT_NULLS_FIRST`	[boolean] Default: False	When a `sort expression` is set, use this option to set whether Null values are counted first or last.
Incremented	`OUTPUT`	[same as input] Default: `[Create temporary layer]`	Specify the output vector layer with the auto increment field. One of: Create Temporary Layer (`TEMPORARY_OUTPUT`) Save to File… Save to Geopackage… Save to PostGIS Table… The file encoding can also be changed here.

23.1.18.1.2. Outputs¶

Label	Имя	Тип	Описание
Incremented	`OUTPUT`	[same as input]	Vector layer with auto incremental field

23.1.18.1.3. Python code¶

Algorithm ID: qgis:addautoincrementalfield

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Изпользование алгоритмов геообработки в консоли for details on how to run processing algorithms from the Python console.

23.1.18.2. Add field to attributes table ¶

Adds a new field to a vector layer.

The name and characteristics of the attribute are defined as parameters.

The new attribute is not added to the input layer but a new layer is generated instead.

23.1.18.2.1. Parameters¶

Label	Имя	Тип	Описание
Input layer	`INPUT`	[vector: any]	The input layer
Field name	`FIELD_NAME`	[string]	Name of the new field
Field type	`FIELD_TYPE`	[enumeration] Default: 0	Type of the new field. You can choose between: 0 — Integer 1 — Float 2 — String
Field length	`FIELD_LENGTH`	[number] Default: 10	Length of the field
Field precision	`FIELD_PRECISION`	[number] Default: 0	Precision of the field. Useful with Float field type.
Added	`OUTPUT`	[same as input] Default: `[Create temporary layer]`	Specify the output vector layer. One of: Create Temporary Layer (`TEMPORARY_OUTPUT`) Save to File… Save to Geopackage… Save to PostGIS Table…… The file encoding can also be changed here.

23.1.18.2.2. Outputs¶

Label	Имя	Тип	Описание
Added	`OUTPUT`	[same as input]	Vector layer with new field added

23.1.18.2.3. Python code¶

Algorithm ID: qgis:addfieldtoattributestable

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Изпользование алгоритмов геообработки в консоли for details on how to run processing algorithms from the Python console.

23.1.18.3. Add unique value index field ¶

Takes a vector layer and an attribute and adds a new numeric field.

Values in this field correspond to values in the specified attribute, so features with the same value for the attribute will have the same value in the new numeric field.

This creates a numeric equivalent of the specified attribute, which defines the same classes.

The new attribute is not added to the input layer but a new layer is generated instead.

23.1.18.3.1. Parameters¶

Label	Имя	Тип	Описание
Input layer	`INPUT`	[vector: any]	The input layer.
Class field	`FIELD`	[tablefield: any]	Features that have the same value for this field will get the same index.
Output field name	`FIELD_NAME`	[string] Default: „NUM_FIELD“	Name of the new field containing the indexes.
Layer with index field	`OUTPUT`	[vector: any] Default: `[Create temporary layer]`	Vector layer with the numeric field containing indexes. One of: Skip Output Create Temporary Layer Save to File… Save to Geopackage… Save to PostGIS Table…… The file encoding can also be changed here.
Class summary	`SUMMARY_OUTPUT`	[table] Default: `[Skip output]`	Specify the table to contain the summary of the class field mapped to the corresponding unique value. One of: Skip Output Create Temporary Layer Save to File… Save to Geopackage… Save to PostGIS Table…… The file encoding can also be changed here.

23.1.18.3.2. Outputs¶

Label

Имя

Тип

Описание

Layer with index field

OUTPUT

[same as input]

Vector layer with the numeric field containing indexes.

Class summary

SUMMARY_OUTPUT

[table]

Default: [Skip Output]

Table with summary of the class field mapped to the corresponding unique value.

23.1.18.3.3. Python code¶

Algorithm ID: qgis:adduniquevalueindexfield

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Изпользование алгоритмов геообработки в консоли for details on how to run processing algorithms from the Python console.

23.1.18.4. Add X/Y fields to layer ¶

Adds X and Y (or latitude/longitude) fields to a point layer. The X/Y fields can be calculated in a different CRS to the layer (e.g. creating latitude/longitude fields for a layer in a projected CRS).

23.1.18.4.1. Parameters¶

Label	Имя	Тип	Описание
Input layer	`INPUT`	[vector: point]	The input layer.
Coordinate system	`CRS`	[crs] Default: «EPSG:4326»	Coordinate reference system to use for the generated x and y fields.
Field prefix Optional	`PREFIX`	[string]	Prefix to add to the new field names to avoid name collisions with fields in the input layer.
Added fields	`OUTPUT`	[vector: point] Default: `[Create temporary layer]`	Specify the output layer. One of: Create Temporary Layer Save to File… Save to Geopackage… Save to PostGIS Table… The file encoding can also be changed here.

23.1.18.4.2. Outputs¶

Label	Имя	Тип	Описание
Added fields	`OUTPUT`	[vector: point]	The output layer - identical to the input layer but with two new double fields, `x` and `y`.

23.1.18.4.3. Python code¶

Algorithm ID: qgis:addxyfieldstolayer

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Изпользование алгоритмов геообработки в консоли for details on how to run processing algorithms from the Python console.

23.1.18.5. Advanced Python field calculator ¶

Adds a new attribute to a vector layer, with values resulting from applying an expression to each feature.

The expression is defined as a Python function.

23.1.18.5.1. Parameters¶

Label	Имя	Тип	Описание
Input layer	`INPUT`	[vector: any]	Input vector layer
Result field name	`FIELD_NAME`	[string] Default: „NewField“	Name of the new field
Field type	`FIELD_TYPE`	[enumeration] Default: 0	Type of the new field. One of: 0 — Integer 1 — Float 2 — String
Field length	`FIELD_LENGTH`	[number] Default: 10	Length of the field
Field precision	`FIELD_PRECISION`	[number] Default: 3	Precision of the field. Useful with Float field type.
Global expression Optional	`GLOBAL`	[string]	The code in the global expression section will be executed only once before the calculator starts iterating through all the features of the input layer. Therefore, this is the correct place to import necessary modules or to calculate variables that will be used in subsequent calculations.
Formula	`FORMULA`	[string]	The Python formula to evaluate. Example: To calculate the area of an input polygon layer you can add: value = $geom.area()
Calculated	`OUTPUT`	[same as input] Default: `[Create temporary layer]`	Specify the vector layer with the new calculated field. One of: Create Temporary Layer Save to File… Save to Geopackage… Save to PostGIS Table…… The file encoding can also be changed here.

23.1.18.5.2. Outputs¶

Label	Имя	Тип	Описание
Calculated	`OUTPUT`	[same as input]	Vector layer with the new calculated field

23.1.18.5.3. Python code¶

Algorithm ID: qgis:advancedpythonfieldcalculator

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Изпользование алгоритмов геообработки в консоли for details on how to run processing algorithms from the Python console.

23.1.18.6. Drop field(s)¶

Takes a vector layer and generates a new one that has the same features but without the selected columns.

23.1.18.6.1. Parameters¶

Label

Имя

Тип

Описание

Input layer

INPUT

[vector: any]

Input vector layer to drop field(s) from

Fields to drop

COLUMN

[tablefield: any] [list]

The field(s) to drop

Remaining fields

OUTPUT

[same as input]

Default: [Create temporary layer]

Specify the output vector layer with the remaining fields. One of:

Create Temporary Layer
Save to File…
Save to Geopackage…
Save to PostGIS Table……

The file encoding can also be changed here.

23.1.18.6.2. Outputs¶

Label	Имя	Тип	Описание
Remaining fields	`OUTPUT`	[same as input]	Vector layer with the remaining fields

23.1.18.6.3. Python code¶

Algorithm ID: qgis:deletecolumn

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Изпользование алгоритмов геообработки в консоли for details on how to run processing algorithms from the Python console.

23.1.18.7. Explode HStore Field ¶

Creates a copy of the input layer and adds a new field for every unique key in the HStore field.

The expected field list is an optional comma separated list. If this list is specified, only these fields are added and the HStore field is updated. By default, all unique keys are added.

The PostgreSQL HStore is a simple key-value store used in PostgreSQL and OGR (when reading an OSM file with the other_tags field.

23.1.18.7.1. Parameters¶

Label	Имя	Тип	Описание
Input layer	`INPUT`	[vector: any]	Input vector layer
HStore field	`FIELD`	[tablefield: any]	The field(s) to drop
Expected list of fields separated by a comma Optional	`EXPECTED_FIELDS`	[string] Default: „“	Comma-separated list of fields to extract. The HStore field will be updated by removing these keys.
Exploded	`OUTPUT`	[same as input] Default: `[Create temporary layer]`	Specify the output vector layer. One of: Create Temporary Layer Save to File… Save to Geopackage… Save to PostGIS Table…… The file encoding can also be changed here.

23.1.18.7.2. Outputs¶

Label	Имя	Тип	Описание
Exploded	`OUTPUT`	[same as input]	Output vector layer

23.1.18.7.3. Python code¶

Algorithm ID: qgis:explodehstorefield

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Изпользование алгоритмов геообработки в консоли for details on how to run processing algorithms from the Python console.

23.1.18.8. Extract binary field ¶

Extracts contents from a binary field, saving them to individual files. Filenames can be generated using values taken from an attribute in the source table or based on a more complex expression.

23.1.18.8.1. Parameters¶

Label	Имя	Тип	Описание
Input layer	`INPUT`	[vector: any]	Input vector layer containing the binary data
Binary field	`FIELD`	[tablefield: any]	Field containing the binary data
File name	`FILENAME`	[expression]	Field or expression-based text to name each output file
Destination folder	`FOLDER`	[folder] Default: `[Save to a temporary folder]`	Folder in which to store the output files. One of: Save to a Temporary Directory Save to Directory… The file encoding can also be changed here.

23.1.18.8.2. Outputs¶

Label	Имя	Тип	Описание
Folder	`FOLDER`	[folder]	The folder that contains the output files.

23.1.18.8.3. Python code¶

Algorithm ID: qgis:extractbinary

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Изпользование алгоритмов геообработки в консоли for details on how to run processing algorithms from the Python console.

23.1.18.9. Feature filter ¶

Filters features from the input layer and redirects them to one or several outputs. If you do not know about any attribute names that are common to all possible input layers, filtering is only possible on the feature geometry and general record mechanisms, such as $id and uuid.

Примечание

This algorithm is only available from the Graphical modeler.

23.1.18.9.1. Parameters¶

Label

Имя

Тип

Описание

Input layer

INPUT

[vector: any]

The input layer.

Outputs and filters

(one or more)

OUTPUT_<name of the filter>

[same as input]

The output layers with filters (as many as there are filters).

23.1.18.9.2. Outputs¶

Label

Имя

Тип

Описание

Вывод

(one or more)

native:filter_1:OUTPUT_<name of filter>

[same as input]

The output layers with filtered features (as many as there are filters).

23.1.18.9.3. Python code¶

Algorithm ID: qgis:featurefilter

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Изпользование алгоритмов геообработки в консоли for details on how to run processing algorithms from the Python console.

23.1.18.10. Field calculator ¶

Opens the field calculator (see Expressions). You can use all the supported expressions and functions.

A new layer is created with the result of the expression.

The field calculator is very useful when used in Редактор моделей.

23.1.18.10.1. Parameters¶

Label	Имя	Тип	Описание
Input layer	`INPUT`	[vector: any]	The layer to calculate on
Output field name	`FIELD_NAME`	[string]	The name of the field for the results
Output field type	`FIELD_TYPE`	[enumeration] Default: 0	The type of the field. One of: 0 — Float 1 — Integer 2 — String 3 — Date
Output field width	`FIELD_LENGTH`	[number] Default: 10	The length of the result field (minimum 0)
Field precision	`FIELD_PRECISION`	[number] Default: 3	The precision of the result field (minimum 0, maximum 15)
Create new field	`NEW_FIELD`	[boolean] Default: True	Should the result field be a new field
Formula	`FORMULA`	[expression]	The formula to use to calculate the result
Output file	`OUTPUT`	[vector: any] Default: `[Save to temporary file]`	Specification of the output layer.

23.1.18.10.2. Outputs¶

Label	Имя	Тип	Описание
Calculated	`OUTPUT`	[vector: any]	Output layer with the calculated field values

23.1.18.10.3. Python code¶

Algorithm ID: qgis:fieldcalculator

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Изпользование алгоритмов геообработки в консоли for details on how to run processing algorithms from the Python console.

23.1.18.11. Refactor fields ¶

Allows editing the structure of the attribute table of a vector layer.

Fields can be modified in their type and name, using a fields mapping.

The original layer is not modified. A new layer is generated, which contains a modified attribute table, according to the provided fields mapping.

Refactor layer fields allows to:

Change field names and types
Add and remove fields
Reorder fields
Calculate new fields based on expressions
Load field list from another layer

Рис. 23.88 Refactor fields dialog¶

23.1.18.11.1. Parameters¶

Label

Имя

Тип

Описание

Input layer

INPUT

[vector: any]

The layer to modify

Fields mapping

FIELDS_MAPPING

[list]

List of output fields with their definitions. The embedded table lists all the fields of the source layer and allows you to edit them:

Click to create a new field.
Click to remove a field.
Use and to change the selected field order.
Click to reset to the default view.

For each of the fields you’d like to reuse, you need to fill the following options:

Source expression (expression) [expression]

Field or expression from the input layer.

Field name (name) [string]

Name of the field in the output layer. By default input field name is kept.

Type (type) [enumeration]

Data type of the output field. One of:

Date (14)
DateTime (16)
Double (6)
Integer (2)
Integer64 (4)
String (10)
Boolean (1)

Length (length) [number]

Length of the output field.

Precision (precision) [number]

Precision of the output field.

Fields from another layer can be loaded into the field list in Load fields from layer.

Refactored

OUTPUT

[vector: any]

Default: [Create temporary layer]

Specification of the output layer. One of:

Create Temporary Layer
Save to File…
Save to Geopackage…
Save to PostGIS Table……

The file encoding can also be changed here.

23.1.18.11.2. Outputs¶

Label	Имя	Тип	Описание
Refactored	`OUTPUT`	[vector: any]	Output layer with refactored fields

23.1.18.11.3. Python code¶

Algorithm ID: qgis:refactorfields

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Изпользование алгоритмов геообработки в консоли for details on how to run processing algorithms from the Python console.

23.1.18.12. Text to float ¶

Modifies the type of a given attribute in a vector layer, converting a text attribute containing numeric strings into a numeric attribute (e.g. „1“ to 1.0).

The algorithm creates a new vector layer so the source one is not modified.

If the conversion is not possible the selected column will have NULL values.

23.1.18.12.1. Parameters¶

Label

Имя

Тип

Описание

Input layer

INPUT

[vector: any]

The input vector layer.

Text attribute to convert to float

FIELD

[tablefield: string]

The string field for the input layer that is to be converted to a float field.

Float from text

OUTPUT

[same as input]

Default: [Create Temporary Layer]

Specify the output layer. One of:

Create Temporary Layer
Save to File…
Save to Geopackage…
Save to PostGIS Table……

The file encoding can also be changed here.

23.1.18.12.2. Outputs¶

Label	Имя	Тип	Описание
Float from text	`OUTPUT`	[same as input]	Output vector layer with the string field converted into a float field

23.1.18.12.3. Python code¶

Algorithm ID: qgis:texttofloat

import processing
processing.run("algorithm_id", {parameter_dictionary})

The algorithm id is displayed when you hover over the algorithm in the Processing Toolbox. The parameter dictionary provides the parameter NAMEs and values. See Изпользование алгоритмов геообработки в консоли for details on how to run processing algorithms from the Python console.