CLI for model discovery in LB4

[dhmlau]

Description / Steps to reproduce / Feature proposal

If I have a sql datatabase (say mysql), how can i create model based on the schema in the database?

Related to: #1921

Updates

Per our team meeting, @raymondfeng is suggesting to implement lb4 discover instead of document the current way for model discovery because not all the generated model json from the discoverSchemas method can be represented correctly in LB4 model (it works for the simple cases, but may not be for other).

There will be 2 stages in lb4 discover:

1. Getting the model JSON from database
   • after creating the datasource, users can simply run this discover command to get the model json.
   • at the same time, model.json created in LB3 can be reused in this case
2. Using the model.json to generate model.ts

@strongloop/loopback-maintainers, thoughts?

---

Original Description

Acceptance Criteria

• Document the instruction in how to useDataSource.discoverSchemas to create model.
  • Possibly create a page under How tos in documentation

References

I've captured some steps in how to use model discovery and Mario added his comments in the following links:
strongloop/v4.loopback.io#50 (comment)
strongloop/v4.loopback.io#50 (comment)

[jannyHou]

@dhmlau I am good with Raymond's suggestion. I've heard of lots of expectations for this feature from LB3 users.

Acceptance Criteria would be:

• Getting the model JSON from database by calling DataSource.discoverSchemas

  • after creating the datasource, users can simply run this discover command to get the model json.
  • at the same time, model.json created in LB3 can be reused in this case

• Using the model.json to generate model.ts

[jannyHou]

Hmm I think this is a dup story of #1921

And a community member is already implementing the cli in a forked repo.

[dhmlau]

@jannyHou , if it's a duplicate, I'm good to close this issue and continue the discussion over #1921.

[bajtos]

@jannyHou @dhmlau Since you closed this issue as a duplicate of #1921, could you please update labels on #1921 to include labels from this issue?

As I see it, this issue was about improving our CLI, while #1921 was more about documenting how to use existing APIs.

[bajtos]

Do we also need to update our issue keeping track of feature parity with LB3? #1949 Are there any other issues and Epics to update?

[bajtos]

AFAICT, there is no CLI command for discovering database schemas and creating model definitions from them. I am reopening this issue.

[dhmlau]

@bajtos, is this PR #2245 fixes this issue?

[dhmlau]

Closing as done as PR #2245 has landed.