Aggregation Expression - $substrBytes

Function Build

Build $substrBytes with the SubstrBytes function from the aggregation package.

// bson.D{bson.E{Key:"prefix", Value:bson.D{bson.E{Key:"$substrBytes", Value:[]interface {}{"$name", 0, 3}}}}}
result := aggregation.SubstrBytes("prefix", "$name", 0, 3)

Method Build (Builder)

Build $substrBytes with the SubstrBytes method from aggregation.NewBuilder().

// bson.D{bson.E{Key:"prefix", Value:bson.D{bson.E{Key:"$substrBytes", Value:[]interface {}{"$name", 0, 3}}}}}
result := aggregation.NewBuilder().
    SubstrBytes("prefix", "$name", 0, 3).
    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.

SubstrBytesWithoutKey

Function build:

// bson.D{bson.E{Key:"$substrBytes", Value:[]any{"$name", 0, 3}}}
expr := aggregation.SubstrBytesWithoutKey("$name", 0, 3)

Method build (Builder):

// bson.D{bson.E{Key:"$substrBytes", Value:[]any{"$name", 0, 3}}}
expr := aggregation.NewBuilder().
    SubstrBytesWithoutKey("$name", 0, 3).
    Build()