Aggregation Expression - $add

Function Build

Build $add with the Add function from the aggregation package.

// bson.D{bson.E{Key:"total", Value:bson.D{bson.E{Key:"$add", Value:[]interface {}{"$price", "$fee"}}}}}
result := aggregation.Add("total", "$price", "$fee")

Method Build (Builder)

Build $add with the Add method from aggregation.NewBuilder().

// bson.D{bson.E{Key:"total", Value:bson.D{bson.E{Key:"$add", Value:[]interface {}{"$price", "$fee"}}}}}
result := aggregation.NewBuilder().
    Add("total", "$price", "$fee").
    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.

AddWithoutKey

Function build:

// bson.D{bson.E{Key:"$add", Value:[]any{"$price", "$fee"}}}
expr := aggregation.AddWithoutKey("$price", "$fee")

Method build (Builder):

// bson.D{bson.E{Key:"$add", Value:[]any{"$price", "$fee"}}}
expr := aggregation.NewBuilder().
    AddWithoutKey("$price", "$fee").
    Build()