Aggregation Expression - $toLower

Function Build

Build $toLower with the ToLower function from the aggregation package.

// bson.D{bson.E{Key:"lowerName", Value:bson.D{bson.E{Key:"$toLower", Value:"$name"}}}}
result := aggregation.ToLower("lowerName", "$name")

Method Build (Builder)

Build $toLower with the ToLower method from aggregation.NewBuilder().

// bson.D{bson.E{Key:"lowerName", Value:bson.D{bson.E{Key:"$toLower", Value:"$name"}}}}
result := aggregation.NewBuilder().
    ToLower("lowerName", "$name").
    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.

ToLowerWithoutKey

Function build:

// bson.D{bson.E{Key:"$toLower", Value:"$name"}}
expr := aggregation.ToLowerWithoutKey("$name")

Method build (Builder):

// bson.D{bson.E{Key:"$toLower", Value:"$name"}}
expr := aggregation.NewBuilder().
    ToLowerWithoutKey("$name").
    Build()