Create model from existing table

[federico-razzoli]

Red should be able to create a model from an existing table.

Motivations:

• a DBA shouldn't be required to learn an ORM to check table structures
• a user could want to use a feature that is not supported by Red, creating the table in SQL
• maybe a table has been created by another application

[jonathanstowe]

The only difficulty with this is that the mechanism to determine the structure of a table varies wildly between database engines, so there will be a lot of code. It might be worth starting with some abstract representation for a model that can generate the code. I made one for Informix years ago and it was a pain.

[FCO]

I think we should create a AST for creating models, and each Driver could read its database and create the AST... than we would have only one code generating the model...

_{Sent with GitHawk}

[jonathanstowe]

Sounds like a plan.

[FCO]

Would it be a cli tool?

_{Sent with GitHawk}

[federico-razzoli]

It's also possible to read the metadata from information_schema tables. Except that SQLite doesn't have information_schema.

[FCO]

@federico-razzoli @jonathanstowe I'm starting implementing it with this commit 67eca7e it seems to be working good (still far from complete).

[FCO]

It's also possible to read the metadata from information_schema tables. Except that SQLite doesn't have information_schema.

It does! It's called sqlite_master! https://github.com/FCO/Red/blob/master/lib/Red/Driver/SQLite/SQLiteMaster.pm6

[jonathanstowe]

I guess that they've done that for the convenience of making a DB dump, but it's not very convenient for doing anything else with it.

[FCO]

https://github.com/FCO/Red/blob/master/bin/red#L26