- Companion
- object
Value members
Abstract methods
Gets a field name for a $group operation representing all unique values that results from applying the given expression to each document in a group of documents that share the same group by key.
Gets a field name for a $group operation representing all unique values that results from applying the given expression to each document in a group of documents that share the same group by key.
- Value Params
- expression
the expression https://docs.mongodb.com/manual/meta/aggregation-quick-reference/#std-label-aggregation-expressions
- fieldName
the field name
- Returns
the accumulator https://docs.mongodb.com/manual/reference/operator/aggregation/addToSet/
Gets a field name for a $group operation representing the average of the values of the given expression when applied to all members of the group.
Gets a field name for a $group operation representing the average of the values of the given expression when applied to all members of the group.
- Value Params
- expression
the expression https://docs.mongodb.com/manual/meta/aggregation-quick-reference/#std-label-aggregation-expressions
- fieldName
the field name
- Returns
the accumulator https://docs.mongodb.com/manual/reference/operator/aggregation/avg/
Merges 2 field accumulators together.
Merges 2 field accumulators together.
- Value Params
- anotherAccumulator
the accumulator to be merged with
- Returns
the accumulator
Gets a field name for a $group operation representing the value of the given expression when applied to the first member of the group.
Gets a field name for a $group operation representing the value of the given expression when applied to the first member of the group.
- Value Params
- expression
the expression https://docs.mongodb.com/manual/meta/aggregation-quick-reference/#std-label-aggregation-expressions
- fieldName
the field name
- Returns
the accumulator https://docs.mongodb.com/manual/reference/operator/aggregation/first/
Gets a field name for a $group operation representing the value of the given expression when applied to the last member of the group.
Gets a field name for a $group operation representing the value of the given expression when applied to the last member of the group.
- Value Params
- expression
the expression https://docs.mongodb.com/manual/meta/aggregation-quick-reference/#std-label-aggregation-expressions
- fieldName
the field name
- Returns
the accumulator https://docs.mongodb.com/manual/reference/operator/aggregation/last/
Gets a field name for a $group operation representing the maximum of the values of the given expression when applied to all members of the group.
Gets a field name for a $group operation representing the maximum of the values of the given expression when applied to all members of the group.
- Value Params
- expression
the expression https://docs.mongodb.com/manual/meta/aggregation-quick-reference/#std-label-aggregation-expressions
- fieldName
the field name
- Returns
the accumulator https://docs.mongodb.com/manual/reference/operator/aggregation/max/
Gets a field name for a $group operation representing the minimum of the values of the given expression when applied to all members of the group.
Gets a field name for a $group operation representing the minimum of the values of the given expression when applied to all members of the group.
- Value Params
- expression
the expression https://docs.mongodb.com/manual/meta/aggregation-quick-reference/#std-label-aggregation-expressions
- fieldName
the field name
- Returns
the accumulator https://docs.mongodb.com/manual/reference/operator/aggregation/min/
Gets a field name for a $group operation representing an array of all values that results from applying an expression to each document in a group of documents that share the same group by key.
Gets a field name for a $group operation representing an array of all values that results from applying an expression to each document in a group of documents that share the same group by key.
- Value Params
- expression
the expression https://docs.mongodb.com/manual/meta/aggregation-quick-reference/#std-label-aggregation-expressions
- fieldName
the field name
- Returns
the accumulator https://docs.mongodb.com/manual/reference/operator/aggregation/push/
Gets a field name for a $group operation representing the sample standard deviation of the values of the given expression when applied to all members of the group.
Gets a field name for a $group operation representing the sample standard deviation of the values of the given expression when applied to all members of the group.
Use if the values encompass the entire population of data you want to represent and do not wish to generalize about a larger population.
- Value Params
- expression
the expression https://docs.mongodb.com/manual/meta/aggregation-quick-reference/#std-label-aggregation-expressions
- fieldName
the field name
- Returns
the accumulator https://docs.mongodb.com/manual/reference/operator/aggregation/stdDevPop/
- Since
3.2
Gets a field name for a $group operation representing the sample standard deviation of the values of the given expression when applied to all members of the group.
Gets a field name for a $group operation representing the sample standard deviation of the values of the given expression when applied to all members of the group.
Use if the values encompass a sample of a population of data from which to generalize about the population.
- Value Params
- expression
the expression https://docs.mongodb.com/manual/meta/aggregation-quick-reference/#std-label-aggregation-expressions
- fieldName
the field name
- Returns
the accumulator https://docs.mongodb.com/manual/reference/operator/aggregation/stdDevSamp/
Gets a field name for a $group operation representing the sum of the values of the given expression when applied to all members of the group.
Gets a field name for a $group operation representing the sum of the values of the given expression when applied to all members of the group.
- Value Params
- expression
the expression https://docs.mongodb.com/manual/meta/aggregation-quick-reference/#std-label-aggregation-expressions
- fieldName
the field name
- Returns
the accumulator https://docs.mongodb.com/manual/reference/operator/aggregation/sum/