e8e4f30dd6
Remote relationships are now supported on SQL Server and BigQuery. The major change though is the re-architecture of remote join execution logic. Prior to this PR, each backend is responsible for processing the remote relationships that are part of their AST. This is not ideal as there is nothing specific about a remote join's execution that ties it to a backend. The only backend specific part is whether or not the specification of the remote relationship is valid (i.e, we'll need to validate whether the scalars are compatible). The approach now changes to this: 1. Before delegating the AST to the backend, we traverse the AST, collect all the remote joins while modifying the AST to add necessary join fields where needed. 1. Once the remote joins are collected from the AST, the database call is made to fetch the response. The necessary data for the remote join(s) is collected from the database's response and one or more remote schema calls are constructed as necessary. 1. The remote schema calls are then executed and the data from the database and from the remote schemas is joined to produce the final response. ### Known issues 1. Ideally the traversal of the IR to collect remote joins should return an AST which does not include remote join fields. This operation can be type safe but isn't taken up as part of the PR. 1. There is a lot of code duplication between `Transport/HTTP.hs` and `Transport/Websocket.hs` which needs to be fixed ASAP. This too hasn't been taken up by this PR. 1. The type which represents the execution plan is only modified to handle our current remote joins and as such it will have to be changed to accommodate general remote joins. 1. Use of lenses would have reduced the boilerplate code to collect remote joins from the base AST. 1. The current remote join logic assumes that the join columns of a remote relationship appear with their names in the database response. This however is incorrect as they could be aliased. This can be taken up by anyone, I've left a comment in the code. ### Notes to the reviewers I think it is best reviewed commit by commit. 1. The first one is very straight forward. 1. The second one refactors the remote join execution logic but other than moving things around, it doesn't change the user facing functionality. This moves Postgres specific parts to `Backends/Postgres` module from `Execute`. Some IR related code to `Hasura.RQL.IR` module. Simplifies various type class function signatures as a backend doesn't have to handle remote joins anymore 1. The third one fixes partial case matches that for some weird reason weren't shown as warnings before this refactor 1. The fourth one generalizes the validation logic of remote relationships and implements `scalarTypeGraphQLName` function on SQL Server and BigQuery which is used by the validation logic. This enables remote relationships on BigQuery and SQL Server. https://github.com/hasura/graphql-engine-mono/pull/1497 GitOrigin-RevId: 77dd8eed326602b16e9a8496f52f46d22b795598 |
||
|---|---|---|
| .circleci | ||
| .github | ||
| architecture | ||
| assets | ||
| cli | ||
| cli-ext | ||
| community | ||
| console | ||
| contrib/metadata-types | ||
| docs | ||
| install-manifests | ||
| rfcs | ||
| scripts | ||
| server | ||
| translations | ||
| .gitignore | ||
| .kodiak.toml | ||
| CHANGELOG.md | ||
| code-of-conduct.md | ||
| CONTRIBUTING.md | ||
| event-triggers.md | ||
| LICENSE | ||
| LICENSE-community | ||
| README.md | ||
| remote-schemas.md | ||
| SECURITY.md | ||
Hasura GraphQL Engine
Hasura GraphQL Engine is a blazing-fast GraphQL server that gives you instant, realtime GraphQL APIs over Postgres, with webhook triggers on database events, and remote schemas for business logic.
Hasura helps you build GraphQL apps backed by Postgres or incrementally move to GraphQL for existing applications using Postgres.
Read more at hasura.io and the docs.
Features
- Make powerful queries: Built-in filtering, pagination, pattern search, bulk insert, update, delete mutations
- Realtime: Convert any GraphQL query to a live query by using subscriptions
- Merge remote schemas: Access custom GraphQL schemas for business logic via a single GraphQL Engine endpoint. Read more.
- Trigger webhooks or serverless functions: On Postgres insert/update/delete events (read more)
- Works with existing, live databases: Point it to an existing Postgres database to instantly get a ready-to-use GraphQL API
- Fine-grained access control: Dynamic access control that integrates with your auth system (eg: auth0, firebase-auth)
- High-performance & low-footprint: ~15MB docker image; ~50MB RAM @ 1000 req/s; multi-core aware
- Admin UI & Migrations: Admin UI & Rails-inspired schema migrations
- Postgres ❤️: Supports Postgres types (PostGIS/geo-location, etc.), turns views to graphs, trigger stored functions or procedures with mutations
Read more at hasura.io and the docs.
Table of contents
Table of Contents
- Quickstart:
- Architecture
- Client-side tooling
- Add business logic
- Demos
- Support & Troubleshooting
- Contributing
- Brand assets
- License
- Translations
Quickstart:
One-click deployment on Hasura Cloud
The fastest and easiest way to try Hasura out is via Hasura Cloud.
-
Click on the following button to deploy GraphQL engine on Hasura Cloud including Postgres add-on or using an existing Postgres database:
-
Open the Hasura console
Click on the button "Launch console" to open the Hasura console.
-
Make your first GraphQL query
Create a table and instantly run your first query. Follow this simple guide.
Other one-click deployment options
Check out the instructions for the following one-click deployment options:
| Infra provider | One-click link | Additional information |
|---|---|---|
| Heroku |  |
docs |
| DigitalOcean |  |
docs |
| Azure |  |
docs |
| Render |  |
docs |
Other deployment methods
For Docker-based deployment and advanced configuration options, see deployment guides or install manifests.
Architecture
The Hasura GraphQL Engine fronts a Postgres database instance and can accept GraphQL requests from your client apps. It can be configured to work with your existing auth system and can handle access control using field-level rules with dynamic variables from your auth system.
You can also merge remote GraphQL schemas and provide a unified GraphQL API.
Client-side tooling
Hasura works with any GraphQL client. We recommend using Apollo Client. See awesome-graphql for a list of clients.
Add business logic
GraphQL Engine provides easy-to-reason, scalable and performant methods for adding custom business logic to your backend:
Remote schemas
Add custom resolvers in a remote schema in addition to Hasura's Postgres-based GraphQL schema. Ideal for use-cases like implementing a payment API, or querying data that is not in your database - read more.
Trigger webhooks on database events
Add asynchronous business logic that is triggered based on database events. Ideal for notifications, data-pipelines from Postgres or asynchronous processing - read more.
Derived data or data transformations
Transform data in Postgres or run business logic on it to derive another dataset that can be queried using GraphQL Engine - read more.
Demos
Check out all the example applications in the community/sample-apps directory.
Realtime applications
-
Group Chat application built with React, includes a typing indicator, online users & new message notifications.
-
Live location tracking app that shows a running vehicle changing current GPS coordinates moving on a map.
-
A realtime dashboard for data aggregations on continuously changing data.
Videos
- Add GraphQL to a self-hosted GitLab instance (3:44 mins)
- Todo app with Auth0 and GraphQL backend (4:00 mins)
- GraphQL on GitLab integrated with GitLab auth (4:05 mins)
- Dashboard for 10million rides with geo-location (PostGIS, Timescale) (3:06 mins)
Support & Troubleshooting
The documentation and community will help you troubleshoot most issues. If you have encountered a bug or need to get in touch with us, you can contact us using one of the following channels:
- Support & feedback: Discord
- Issue & bug tracking: GitHub issues
- Follow product updates: @HasuraHQ
- Talk to us on our website chat
We are committed to fostering an open and welcoming environment in the community. Please see the Code of Conduct.
If you want to report a security issue, please read this.
Contributing
Check out our contributing guide for more details.
Brand assets
Hasura brand assets (logos, the Hasura mascot, powered by badges etc.) can be found in the assets/brand folder. Feel free to use them in your application/website etc. We'd be thrilled if you add the "Powered by Hasura" badge to your applications built using Hasura. ❤️
<!-- For light backgrounds -->
<a href="https://hasura.io">
<img width="150px" src="https://graphql-engine-cdn.hasura.io/img/powered_by_hasura_blue.svg" />
</a>
<!-- For dark backgrounds -->
<a href="https://hasura.io">
<img width="150px" src="https://graphql-engine-cdn.hasura.io/img/powered_by_hasura_white.svg" />
</a>
License
The core GraphQL Engine is available under the Apache License 2.0 (Apache-2.0).
All other contents (except those in server, cli and
console directories) are available under the MIT License.
This includes everything in the docs and community
directories.
Translations
This readme is available in the following translations:
- Japanese 🇯🇵 (🙏 @moksahero)
- French 🇫🇷 (🙏 @l0ck3)
- Bosnian 🇧🇦 (🙏 @hajro92)
- Russian 🇷🇺 (🙏 @highflyer910)
- Greek 🇬🇷 (🙏 @MIP2000)
- Spanish 🇲🇽(🙏 @ferdox2)
- Indonesian 🇮🇩 (🙏 @anwari666)
- Brazilian Portuguese 🇧🇷 (🙏 @rubensmp)
- German 🇩🇪 (🙏 @FynnGrandke)
- Chinese 🇨🇳 (🙏 @jagreetdg & @johnbanq)
- Turkish 🇹🇷 (🙏 @berat)
- Korean 🇰🇷 (🙏 @라스크)
Translations for other files can be found here.