https://github.com/pdcalado/perry
A pet project to explore entity relationship concepts
https://github.com/pdcalado/perry
entity-relationship graphql grpc rust typescript wasm
Last synced: about 2 months ago
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A pet project to explore entity relationship concepts
- Host: GitHub
- URL: https://github.com/pdcalado/perry
- Owner: pdcalado
- License: mit
- Created: 2023-02-01T18:14:04.000Z (about 2 years ago)
- Default Branch: main
- Last Pushed: 2023-02-01T22:15:40.000Z (about 2 years ago)
- Last Synced: 2025-03-13T09:04:09.844Z (about 2 months ago)
- Topics: entity-relationship, graphql, grpc, rust, typescript, wasm
- Language: TypeScript
- Homepage:
- Size: 482 KB
- Stars: 2
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Perry
Perry was used as a testing site to explore entity relationship concepts.
## How it works
1. Write a JSON file specifying the entities and relationships, looking like [data.json](demo/data.json).
1. Create JSON schemas from the spec.
1. Create SQL schemas from the spec.
1. Create GraphQL schemas from the spec.
1. Use a generic UI to create/read/update objects (folder [ui](ui/)).
Perry includes:
* Models API to simply serve the spec mentioned above ([models](models/)).
* a shared internal library ([perrydl](perrydl)) in Typescript and Rust (WASM) that:
* generates SQL schema from the spec
* generates GraphQL schemas from spec
* generates JSON schemas from the spec
* Dupe API ([dupe](dupe/)) which is an extremely unoptimized backend that:
* queries the model from Models API
* uses [perrydl](perrydl) to generate SQL schema, GraphQL schema and JSON schemas from the spec
* bootstraps a sqliteDB using the generated SQL
* serves a GraphQL API using the generated GraphQL schema (to serve and mutate the data in the sqliteDB)
* uses JSON schemas to validate input data
* allows bulk insert and update using CSVs
* captures data changes and sends to an in-memory [event-broker](https://gitlab.com/pedrocalado/mrbig/-/tree/main/examples/event-broker) (gRPC-Web)
* A user interface in Typescript+React+Recoil [ui](ui/)
* queries Models API to create entity relationship internal representation
* allows exploring entities using a graph like structure
* generates forms to create data objects
* uses tables and filters to present data objects
* listens to events served by an in-memory [event-broker](https://gitlab.com/pedrocalado/mrbig/-/tree/main/examples/event-broker) (gRPC-Web)
```mermaid
graph TD
S(Data Spec in json) -->|served by| M[Models API]
D[Dupe] -->|query models| M
D -->|create DB and store data| Q[sqliteDB]
D -->|publish mutation events| E[Event Broker]
U[UI] -->|query model| M
U -->|query data using GraphQL| D
U -->|consume mutation events| E
```
## Bugs and limitations
Perry is not production ready and should not be used in a production environment, it's just exploration:
- search by text is flawed and applies to first column only
- gRPC stream lacks keep alive
- gear icon on text search is useless
- items cannot be dragged & dropped even though there are drop zones
- sessions are volatile, if you reload tabs are lost
- mutation events published by dupe are meant as a "poor man's CDC" but are not consistent (if dupe fails to publish them, they won't be retried)
- the event broker is an in-memory broker with short-lived historic data
- changing fields which are unique yields cryptic errors
This project is not being actively maintained.
# Demo
Go to https://perry-demo.pages.dev and use the credentials:
* user: `[email protected]`
* password: `1veryrandomPassword4perry`
The demo is fairly limited:
- data resets every hour
- data sample does not explore all entities and relations in the data spec
- backend requests are rate limited to prevent abuse
- app is halted if high network traffic is detected
- translation to de_DE comes straight from https://translate.i18next.com/