[Ready] Add support for building in "offline/decoupled" mode

[abonander]

TODO:

• add support in sqlx-macros
• rebase on develop (will necessitate creating a new PR) master
• implement cargo sqlx prepare
• integration test
• document offline mode

[phated]

Love this work! Let me know if I can help out by testing it against my side project or in any other ways.

[phated]

Thanks for looking into that! I'm just glad I can help in some small way. 😄

[abonander]

@JesperAxelsson I've made some significant changes in this PR to cargo-sqlx (renamed to sqlx-cli) if you'd like to look it over; it'll be rebased after merging your pending PRs.

[JesperAxelsson]

@JesperAxelsson I've made some significant changes in this PR to cargo-sqlx (renamed to sqlx-cli) if you'd like to look it over; it'll be rebased after merging your pending PRs.

Looking good to me!
One thing we should take a look at later is the url handling. Right now sqlx lib and the cli use different ways to parse the url. While it's fine now it might cause issues. And the url parsing I wrote is really fragile ^^.
The same can be said about get_db_kind() and get() for migrator, a user would quite confused if one failed while another accepted their url.
But there is already some work being done to create a more robust url parser if I remember correctly?

[phated]

@abonander I've been doing some more stuff with this and it seems that the last changes have made it so this command can't be run at the project root of a cargo workspace. Any ideas how that could be made to work again?

[abonander]

@phated what error do you get?

[phated]

@abonander thanks for the quick response. Here's the error I see when running it in the root of my workspace.

error: manifest path /Users/phated/github/twentyfive-stars/Cargo.toml is a virtual manifest, but this command requires running against an actual package in this workspace
Error: cargo check failed with status: exit code: 101