drf-aggregation 0.5.0

DRF ViewSet for getting aggregations

DRF Mixin for getting aggregations

List of possible aggregations:

• count

• sum

• average

• minimum

• maximum

• percentile (work only on PostgreSQL)

• percent

Additional features

• grouping by multiple fields

• grouping by date fields with the required precision (from a second to a year)

• display of top-N records, with the ability to show the rest of the records as a single group

Installing

For installing use pip

$ pip install drf-aggregation

Usage

Create a ViewSet using a ViewSet from a package or by adding a mixin to an existing one

from drf_aggregation.mixins import AggregationMixin
from drf_aggregation.viewsets import AggregationViewSet


class MyCustomUserViewSet(AggregationMixin, GenericViewSet):
    queryset = User.objects.all()
    serializer_class = UserSerializer

class UserViewSet(AggregationViewSet):
    queryset = User.objects.all()
    serializer_class = UserSerializer

Register url

from drf_aggregation.routers import AggregationRouter


aggregation_router = AggregationRouter()
aggregation_router.register("user", UserViewSet)

urlpatterns = [
    path("my/custom/endpoint", UserViewSet.as_view({"get": "aggregation"})),
]

urlpatterns += aggregation_router.urls

Get aggregations

# Get the number of users
/user/aggregation?aggregation=count

# Total cost of orders
/order/aggregation?aggregation=sum&aggregationField=price

# Earliest registration date
/user/aggregation?aggregation=minimum&aggregationField=date_joined

# Last travel date
/trip/aggregation?aggregation=maximum&aggregationField=duration

# Median salary
/position/aggregation?aggregation=percentile&aggregationField=salary&percentile=0.5

# Number of tickets by state
/ticket/aggregation?aggregation=count&groupByFields=state

# Top 5 ticket executors
/ticket/aggregation?aggregation=count&groupByFields=assigned_to&limit=5&limitByField=assigned_to&order=desc

# Percentage of open tickets by service
/ticket/aggregation?aggregation=percent&groupByFields=service&additionalFilter={"type":"operator","operator":{"attribute":"state","operator":"=","value":"open"}}

# Life expectancy depending on the year of birth
/person/aggregation?aggregation=average&aggregationField=age&annotations={"birth_year":{"field":"birth_date","kind":"year"}}&groupByFields=birth_year

Query parameters

• aggregation - aggregation type, one of:

  • count

  • sum

  • average

  • minimum

  • maximum

  • percentile

  • percent - return two additional values: “numerator” and “denominator”

• aggregationField - mandatory for aggregations: sum, average, minimum, maximum, percentile

• percentile - from 0 to 1, mandatory for percentile

• outputType - currently only accepts “floats” to properly aggregate integer fields, used for percentile only

• additionalFilter - filter parser is used from package drf-complex-filter, mandatory for percent

The following additional options are available for all aggregation types

• groupBy - comma-separated list of fields, used to group the result by one or more fields, mandatory if limit is set

• annotations - additional annotations for truncating date fields, using Trunc method from Django, format see examples above

• limit - limits the output to the number of groups of records passed

  • limitByField - field for selecting the values that will remain, mandatory if limit is set

  • order - sorting direction of values: “asc” or “desc”

  • showOther - show groups not included in the top by one category or not

  • otherGroupName - label for a group with records not included in the top

Supported field types

Aggregations are available on the following field types:

• IntegerField

• FloatField

• DateField - only minimum and maximum

• DateTimeField - only minimum and maximum

• DurationField