QGIS Algorithm provided by QGIS (native c++) Aggregate (native:aggregate). This algorithm take a vector or table layer and aggregate features based on a group by expression. Features for which group by expression return the same value are grouped together. It is possible to group all source features together using constant value in group by parameter, example: NULL. It is also possible to group features using multiple fields using Array function, example: Array("Field1", "Field2"). Geometries (if present) are combined into one multipart geometry for each group. Output attributes are computed depending on each given aggregate definition.
qgis_aggregate(
INPUT = qgisprocess:::qgis_default_value(),
GROUP_BY = qgisprocess:::qgis_default_value(),
AGGREGATES = qgisprocess:::qgis_default_value(),
OUTPUT = qgisprocess:::qgis_default_value(),
...,
.complete_output = .complete_output_option(),
.quiet = .quiet_option(),
.messages = .message_option()
)source - Input layer. Path to a vector layer.
expression - Group by expression (NULL to group all features). A valid QGIS expression string, e.g "road_name" = 'MAIN RD'.
aggregates - Aggregates. .
sink - Aggregated. Path for new vector layer.
further parameters passed to qgisprocess::qgis_run_algorithm()
logical specifying if complete out of qgisprocess::qgis_run_algorithm() should be used (TRUE) or first output (most likely the main) should read (FALSE). Default value is TRUE.
logical specifying if parameter .quiet for qgisprocess::qgis_run_algorithm() Default value is TRUE.
logical specifying if messages from qgisprocess::qgis_run_algorithm() should be printed (TRUE) or not (FALSE). Default value is FALSE.