graphql-engine/server/src-lib/Hasura/Backends/MySQL
David Overton 346804fc67 Support nested object fields in DC API and use this to implement nest…
## Description

This change adds support for nested object fields in HGE IR and Schema Cache, the Data Connectors backend and API, and the MongoDB agent.

### Data Connector API changes

- The `/schema` endpoint response now includes an optional set of GraphQL type definitions. Table column types can refer to these definitions by name.
- Queries can now include a new field type `object` which contains a column name and a nested query. This allows querying into a nested object within a field.

### MongoDB agent changes

- Add support for querying into nested documents using the new `object` field type.

### HGE changes

- The `Backend` type class has a new type family `XNestedObjects b` which controls whether or not a backend supports querying into nested objects. This is currently enabled only for the `DataConnector` backend.
- For backends that support nested objects, the `FieldInfo` type gets a new constructor `FINestedObject`, and the `AnnFieldG` type gets a new constructor `AFNestedObject`.
- If the DC `/schema` endpoint returns any custom GraphQL type definitions they are stored in the `TableInfo` for each table in the source.
- During schema cache building, the function `addNonColumnFields` will check whether any column types match custom GraphQL object types stored in the `TableInfo`. If so, they are converted into `FINestedObject` instead of `FIColumn` in the `FieldInfoMap`.
- When building the `FieldParser`s from `FieldInfo` (function `fieldSelection`) any `FINestedObject` fields are converted into nested object parsers returning `AFNestedObject`.
- The `DataConnector` query planner converts `AFNestedObject` fields into `object` field types in the query sent to the agent.

## Limitations

### HGE not yet implemented:
- Support for nested arrays
- Support for nested objects/arrays in mutations
- Support for nested objects/arrays in order-by
- Support for filters (`where`) in nested objects/arrays
- Support for adding custom GraphQL types via track table metadata API
- Support for interface and union types
- Tests for nested objects

### Mongo agent not yet implemented:

- Generate nested object types from validation schema
- Support for aggregates
- Support for order-by
- Configure agent port
- Build agent in CI
- Agent tests for nested objects and MongoDB agent

PR-URL: https://github.com/hasura/graphql-engine-mono/pull/7844
GitOrigin-RevId: aec9ec1e4216293286a68f9b1af6f3f5317db423
2023-04-11 01:30:37 +00:00
..
DataLoader Upgrade Ormolu to v0.5. 2022-11-02 20:55:13 +00:00
Instances feature(server): Get _all_ source tables 2023-04-05 20:16:14 +00:00
Schema feature(server): Get _all_ source tables 2023-04-05 20:16:14 +00:00
Types Remove NativeQueryMetadata 2023-02-15 16:27:47 +00:00
Connection.hs server: plumb StoredIntrospection while building the Schema Cache 2023-01-20 14:52:36 +00:00
FromIr.hs rename naqi to logimo part 3 - data types 2023-02-22 13:46:54 +00:00
Meta.hs Support nested object fields in DC API and use this to implement nest… 2023-04-11 01:30:37 +00:00
Plan.hs Move Hasura.GraphQL.Parser.Column to .RQL.IR. and .GraphQL.Schema. 2022-05-30 22:07:57 +00:00
SQL.hs Remove strictness annotations from data types in the Hasura.Backends hierarchy 2022-07-29 14:06:23 +00:00
ToQuery.hs Upgrade Ormolu to v0.5. 2022-11-02 20:55:13 +00:00
Types.hs server, pro: actually reformat the code-base using ormolu 2021-09-23 22:57:37 +00:00