You are mixing GraphQL and DQL. The GraphQL type definition is translated to a DQL type definition. The DQL mutation then uses the generated DQL type definition, not the GraphQL type definition.
See this link: GraphQL on Existing Dgraph - GraphQL
You are mixing GraphQL and DQL. The GraphQL type definition is translated to a DQL type definition. The DQL mutation then uses the generated DQL type definition, not the GraphQL type definition.
See this link: GraphQL on Existing Dgraph - GraphQL