Function validateSchemaForUnique

worker/mutation.go:460–504

(prevSchema pb.SchemaUpdate, currentSchema *pb.SchemaUpdate)

}

func validateSchemaForUnique(prevSchema pb.SchemaUpdate, currentSchema *pb.SchemaUpdate) error {
	validTokenizer := func(tokenizers []string) bool {
		for _, value := range tokenizers {
			if value == "hash" || value == "exact" || value == "int" {
				return true
			}
		}
		return false
	}
	if prevSchema.Predicate != "" {
		if prevSchema.Upsert && !currentSchema.Upsert {
			return errors.Errorf("could not drop @upsert from [%v] predicate when @unique directive specified",
				x.ParseAttr(currentSchema.Predicate))
		}

		if prevSchema.Unique && !validTokenizer(currentSchema.Tokenizer) {
			return errors.Errorf("could not drop index %v from [%v] predicate when @unique directive specified",
				prevSchema.Tokenizer, x.ParseAttr(currentSchema.Predicate))
		}
	}
	if !currentSchema.Upsert {
		currentSchema.Upsert = true
	}
	switch currentSchema.ValueType {
	case pb.Posting_STRING:
		if len(currentSchema.Tokenizer) == 0 ||
			(len(currentSchema.Tokenizer) > 0 && !validTokenizer(currentSchema.Tokenizer)) {

			return errors.Errorf("index for predicate [%v] is missing, add either hash or exact index with @unique",
				x.ParseAttr(currentSchema.Predicate))
		} else {
			return nil
		}

	case pb.Posting_INT:
		if len(currentSchema.Tokenizer) == 0 {
			return errors.Errorf("index for predicate [%v] is missing, add int index with @unique",
				x.ParseAttr(currentSchema.Predicate))
		} else {
			return nil
		}
	}

	return errors.Errorf("@unique directive not supported on [%v] type predicate", currentSchema.ValueType.String())
}

// ValidateAndConvert checks compatibility or converts to the schema type if the storage type is
// specified. If no storage type is specified then it converts to the schema type.