PostgreSQL specific aggregation functions¶

ArrayAgg¶

class ArrayAgg(expression, distinct=False, filter=None, ordering=(), **extra)[código fonte]¶

Returns a list of values, including nulls, concatenated into an array.

distinct¶

An optional boolean argument that determines if array values will be distinct. Defaults to False.

ordering¶

New in Django 2.2.

An optional string of a field name (with an optional "-" prefix which indicates descending order) or an expression (or a tuple or list of strings and/or expressions) that specifies the ordering of the elements in the result list.

Exemplos:

'some_field'
'-some_field'
from django.db.models import F
F('some_field').desc()

BitAnd¶

class BitAnd(expression, filter=None, **extra)[código fonte]¶

Returns an int of the bitwise AND of all non-null input values, or None if all values are null.

BitOr¶

class BitOr(expression, filter=None, **extra)[código fonte]¶

Returns an int of the bitwise OR of all non-null input values, or None if all values are null.

BoolAnd¶

class BoolAnd(expression, filter=None, **extra)[código fonte]¶

Returns True, if all input values are true, None if all values are null or if there are no values, otherwise False .

BoolOr¶

class BoolOr(expression, filter=None, **extra)[código fonte]¶

Returns True if at least one input value is true, None if all values are null or if there are no values, otherwise False.

JSONBAgg¶

class JSONBAgg(expressions, filter=None, **extra)[código fonte]¶

Returns the input values as a JSON array. Requires PostgreSQL ≥ 9.5.

StringAgg¶

class StringAgg(expression, delimiter, distinct=False, filter=None, ordering=())[código fonte]¶

Returns the input values concatenated into a string, separated by the delimiter string.

delimiter¶

Required argument. Needs to be a string.

distinct¶

An optional boolean argument that determines if concatenated values will be distinct. Defaults to False.

ordering¶

New in Django 2.2.

An optional string of a field name (with an optional "-" prefix which indicates descending order) or an expression (or a tuple or list of strings and/or expressions) that specifies the ordering of the elements in the result string.

Examples are the same as for ArrayAgg.ordering.

y and x¶

The arguments y and x for all these functions can be the name of a field or an expression returning a numeric data. Both are required.

Corr¶

class Corr(y, x, filter=None)[código fonte]¶

Returns the correlation coefficient as a float, or None if there aren’t any matching rows.

CovarPop¶

class CovarPop(y, x, sample=False, filter=None)[código fonte]¶

Returns the population covariance as a float, or None if there aren’t any matching rows.

Has one optional argument:

sample¶

By default CovarPop returns the general population covariance. However, if sample=True, the return value will be the sample population covariance.

RegrAvgX¶

class RegrAvgX(y, x, filter=None)[código fonte]¶

Returns the average of the independent variable (sum(x)/N) as a float, or None if there aren’t any matching rows.

RegrAvgY¶

class RegrAvgY(y, x, filter=None)[código fonte]¶

Returns the average of the dependent variable (sum(y)/N) as a float, or None if there aren’t any matching rows.

RegrCount¶

class RegrCount(y, x, filter=None)[código fonte]¶

Returns an int of the number of input rows in which both expressions are not null.

RegrIntercept¶

class RegrIntercept(y, x, filter=None)[código fonte]¶

Returns the y-intercept of the least-squares-fit linear equation determined by the (x, y) pairs as a float, or None if there aren’t any matching rows.

RegrR2¶

class RegrR2(y, x, filter=None)[código fonte]¶

Returns the square of the correlation coefficient as a float, or None if there aren’t any matching rows.

RegrSlope¶

class RegrSlope(y, x, filter=None)[código fonte]¶

Returns the slope of the least-squares-fit linear equation determined by the (x, y) pairs as a float, or None if there aren’t any matching rows.

RegrSXX¶

class RegrSXX(y, x, filter=None)[código fonte]¶

Returns sum(x^2) - sum(x)^2/N (“sum of squares” of the independent variable) as a float, or None if there aren’t any matching rows.

RegrSXY¶

class RegrSXY(y, x, filter=None)[código fonte]¶

Returns sum(x*y) - sum(x) * sum(y)/N (“sum of products” of independent times dependent variable) as a float, or None if there aren’t any matching rows.

RegrSYY¶

class RegrSYY(y, x, filter=None)[código fonte]¶

Returns sum(y^2) - sum(y)^2/N (“sum of squares” of the dependent variable) as a float, or None if there aren’t any matching rows.