Aggregation Expression - $avg

Function Build

Build $avg with the Avg function from the aggregation package.

// bson.D{bson.E{Key:"avgScore", Value:bson.D{bson.E{Key:"$avg", Value:"$score"}}}}
result := aggregation.Avg("avgScore", "$score")

Method Build (Builder)

Build $avg with the Avg method from aggregation.NewBuilder().

// bson.D{bson.E{Key:"avgScore", Value:bson.D{bson.E{Key:"$avg", Value:"$score"}}}}
result := aggregation.NewBuilder().
    Avg("avgScore", "$score").
    Build()

Build Without Key

When an expression needs to be passed as an argument to another expression, use a WithoutKey variant to build an expression fragment without an output field name.

AvgWithoutKey

Function build:

// bson.D{bson.E{Key:"$avg", Value:"$score"}}
expr := aggregation.AvgWithoutKey("$score")

Method build (Builder):

// bson.D{bson.E{Key:"$avg", Value:"$score"}}
expr := aggregation.NewBuilder().
    AvgWithoutKey("$score").
    Build()