MongoAccumulators
Definition of the accumulators in Bson that are used in MongoDB aggregation operations.
avg
avg(fieldName: string, expression: string) : com.mongodb.client.model.BsonField
Description
Creates an accumulator that calculates the average of the values of a field.
How To Use
_mongo.accumulators().avg('averagePrice', '$price');
Attributes
| NAME | TYPE | DESCRIPTION |
|---|---|---|
| fieldName | string | The output field name. |
| expression | string | The input field expression. |
Return
( com.mongodb.client.model.BsonField )
The BsonField accumulator.
bottom
bottom(fieldName: string, sortBy: org.bson.conversions.Bson, outExpression: string) : com.mongodb.client.model.BsonField
Description
Returns the bottom document based on the specified sort.
How To Use
_mongo.accumulators().bottom('loser', _mongo.sorts().ascending('score'), '$playerId');
Attributes
| NAME | TYPE | DESCRIPTION |
|---|---|---|
| fieldName | string | The output field name. |
| sortBy | org.bson.conversions.Bson | The sort to apply. |
| outExpression | string | The output field expression. |
Return
( com.mongodb.client.model.BsonField )
The BsonField accumulator.
bottomN
bottomN(fieldName: string, sortBy: org.bson.conversions.Bson, outExpression: string, nExpression: long) : com.mongodb.client.model.BsonField
Description
Returns the bottom N documents based on the specified sort.
How To Use
_mongo.accumulators().bottomN('bottomThree', _mongo.sorts().ascending('score'), '$playerId', 3);
Attributes
| NAME | TYPE | DESCRIPTION |
|---|---|---|
| fieldName | string | The output field name. |
| sortBy | org.bson.conversions.Bson | The sort to apply. |
| outExpression | string | The output field expression. |
| nExpression | long | The number of values to return. |
Return
( com.mongodb.client.model.BsonField )
The BsonField accumulator.
first
first(fieldName: string, expression: string) : com.mongodb.client.model.BsonField
Description
Gets the field value from the first document in the ordered list.
How To Use
_mongo.accumulators().first('latestTotal', '$totalAmount');
Attributes
| NAME | TYPE | DESCRIPTION |
|---|---|---|
| fieldName | string | The output field name. |
| expression | string | The input field expression. |
Return
( com.mongodb.client.model.BsonField )
The BsonField accumulator.
firstN
firstN(fieldName: string, inExpression: string, nExpression: long) : com.mongodb.client.model.BsonField
Description
Gets the first N values of the field from the first documents in the ordered list.
How To Use
_mongo.accumulators().firstN('topThreeOrders', '$totalAmount', 3);
Attributes
| NAME | TYPE | DESCRIPTION |
|---|---|---|
| fieldName | string | The output field name. |
| inExpression | string | The input field expression. |
| nExpression | long | The number of values to return. |
Return
( com.mongodb.client.model.BsonField )
The BsonField accumulator.
last
last(fieldName: string, expression: string) : com.mongodb.client.model.BsonField
Description
Gets the field value from the last document in the ordered list.
How To Use
_mongo.accumulators().last('lastTotal', '$totalAmount');
Attributes
| NAME | TYPE | DESCRIPTION |
|---|---|---|
| fieldName | string | The output field name. |
| expression | string | The input field expression. |
Return
( com.mongodb.client.model.BsonField )
The BsonField accumulator.
lastN
lastN(fieldName: string, inExpression: string, nExpression: long) : com.mongodb.client.model.BsonField
Description
Gets the last N values of the field from the last documents in the ordered list.
How To Use
_mongo.accumulators().lastN('lastThreeOrders', '$totalAmount', 3);
Attributes
| NAME | TYPE | DESCRIPTION |
|---|---|---|
| fieldName | string | The output field name. |
| inExpression | string | The input field expression. |
| nExpression | long | The number of values to return. |
Return
( com.mongodb.client.model.BsonField )
The BsonField accumulator.
max
max(fieldName: string, expression: string) : com.mongodb.client.model.BsonField
Description
Creates an accumulator that returns the maximum value of the field.
How To Use
_mongo.accumulators().max('maxPrice', '$price');
Attributes
| NAME | TYPE | DESCRIPTION |
|---|---|---|
| fieldName | string | The output field name. |
| expression | string | The input field expression. |
Return
( com.mongodb.client.model.BsonField )
The BsonField accumulator.
maxN
maxN(fieldName: string, inExpression: string, nExpression: long) : com.mongodb.client.model.BsonField
Description
Returns the top N values of the field.
How To Use
_mongo.accumulators().maxN('topThreePrices', '$price', 3);
Attributes
| NAME | TYPE | DESCRIPTION |
|---|---|---|
| fieldName | string | The output field name. |
| inExpression | string | The input field expression. |
| nExpression | long | The number of values to return. |
Return
( com.mongodb.client.model.BsonField )
The BsonField accumulator.
min
min(fieldName: string, expression: string) : com.mongodb.client.model.BsonField
Description
Creates an accumulator that returns the minimum value of the field.
How To Use
_mongo.accumulators().min('minPrice', '$price');
Attributes
| NAME | TYPE | DESCRIPTION |
|---|---|---|
| fieldName | string | The output field name. |
| expression | string | The input field expression. |
Return
( com.mongodb.client.model.BsonField )
The BsonField accumulator.
minN
minN(fieldName: string, inExpression: string, nExpression: long) : com.mongodb.client.model.BsonField
Description
Returns the bottom N values of the field.
How To Use
_mongo.accumulators().minN('bottomThreePrices', '$price', 3);
Attributes
| NAME | TYPE | DESCRIPTION |
|---|---|---|
| fieldName | string | The output field name. |
| inExpression | string | The input field expression. |
| nExpression | long | The number of values to return. |
Return
( com.mongodb.client.model.BsonField )
The BsonField accumulator.
sum
sum(fieldName: string, expression: string) : com.mongodb.client.model.BsonField
Description
Creates an accumulator that calculates the sum of the values of a field.
How To Use
_mongo.accumulators().sum('totalPrice', '$price');
Attributes
| NAME | TYPE | DESCRIPTION |
|---|---|---|
| fieldName | string | The output field name. |
| expression | string | The input field expression. |
Return
( com.mongodb.client.model.BsonField )
The BsonField accumulator.
top
top(fieldName: string, sortBy: org.bson.conversions.Bson, outExpression: string) : com.mongodb.client.model.BsonField
Description
Returns the top document based on the specified sort.
How To Use
_mongo.accumulators().top('winner', _mongo.sorts().descending('score'), '$playerId');
Attributes
| NAME | TYPE | DESCRIPTION |
|---|---|---|
| fieldName | string | The output field name. |
| sortBy | org.bson.conversions.Bson | The sort to apply. |
| outExpression | string | The output field expression. |
Return
( com.mongodb.client.model.BsonField )
The BsonField accumulator.
topN
topN(fieldName: string, sortBy: org.bson.conversions.Bson, outExpression: string, nExpression: long) : com.mongodb.client.model.BsonField
Description
Returns the top N documents based on the specified sort.
How To Use
_mongo.accumulators().topN('topThree', _mongo.sorts().descending('score'), '$playerId', 3);
Attributes
| NAME | TYPE | DESCRIPTION |
|---|---|---|
| fieldName | string | The output field name. |
| sortBy | org.bson.conversions.Bson | The sort to apply. |
| outExpression | string | The output field expression. |
| nExpression | long | The number of values to return. |
Return
( com.mongodb.client.model.BsonField )
The BsonField accumulator.