Method DistinctOn

datastore/query.go:214–218

DistinctOn returns a derivative query that yields de-duplicated entities with respect to the set of the specified fields. It is only used for projection queries. The field list should be a subset of the projected field list. DistinctOn cannot be used with Distinct.

(fieldNames ...string)

// queries. The field list should be a subset of the projected field list.
// DistinctOn cannot be used with Distinct.
func (q *Query) DistinctOn(fieldNames ...string) *Query {
	q = q.clone()
	q.distinctOn = fieldNames
	return q
}

// KeysOnly returns a derivative query that yields only keys, not keys and
// entities. It cannot be used with projection queries.