5 Oracle Database Support for GraphQL – Constraints and Limitations

This topic summarizes key constraints and limitations for Oracle Database Support for GraphQL.

Query Structure & Syntax

• Multiple empty lines between tokens are not allowed.
• Empty strings ("") are not supported.

Supported Features

• Multi-root queries are not supported.
• The following GraphQL features are not supported:
  • Fragments
  • Interfaces, Unions, and Enums
  • Mutations
  • Subscriptions

Types & Fields

• An internal __typename field exists for all types but is not exposed in the schema.
• Scalar fields cannot accept arguments.

Input & Arguments

• Arguments cannot have directives.
• Passing JSON objects as arguments is not supported.
• Empty lists ([]) are not supported.
• Duplicate fields in input result in an error (no merging of identical values).

Directives

• @skip and @include do not accept variables.

Response Format

• Responses do not follow the standard GraphQL "data" wrapper.
• A single JSON object is returned with the root type directly.
• Error representation differs from the GraphQL specification.