`referential_key_table_name` empty for some schemas (panic on Option::unwrap on None during migration) since sea-schema 0.14.2

[Patrick-Lehner-Woven-by-Toyota]

Hi everyone, thanks so much for your great work on the entire SeaQL project ❤️

Description

This week we found an issue where sea-orm-cli generate entity fails with a panic in sea-schema's table_constraints.rs here when it tries to unwrap the Option result.referential_key_table_name that is None in our case.

This seems to be the same error behavior as described in https://github.com/SeaQL/sea-orm/discussions/2131.

Steps to Reproduce

1. Have a situation where one table T1 has a foreign key (FK) that references a column C in another table T2, where there is a unique index on C but not a unique key (which postgres lets you do, see this SO answer)
2. Run sea-orm-cli generate entity

Expected Behavior

The entities should be generated according to the schema.

If there is a problem with the schema, an informative error message should be printed.

Actual Behavior

The tool panics without any useful error message.

Reproduces How Often

Always (with our schema)

Versions

We are using postgres 14.5.

This issue occurs for us when sea-orm-cli is using [email protected] and does not occur when sea-orm-cli is using [email protected].

We first noticed this after one of our team members recently installed the latest version of sea-orm-cli (0.12.15) where this issue occurred, while on another person's machine it was still working with an older installation of [email protected]. When that person upgraded to latest, they also experienced the error.

We also noticed that when you install an older version of sea-orm-cli with only the version selector (e.g. cargo install [email protected]), Cargo will still use the newest dependencies that match the tool's dependencies spec and will not use the versions that it was published with.

Since sea-orm-cli used the dependency sea-schema = { version = "0.14.0" } (see here) up to 0.12.11, the newer patch version 0.14.2 of sea-schema still matches that version specifier and gets used.

To install an older sea-orm-cli with an older sea-schema for comparative testing, you can use the --locked switch to make Cargo use the versions used at time of publishing, e.g. cargo install --locked [email protected].

Additional Information

Here's a shell script that creates a postgres docker container, creates two tables with the unique/FK combination that causes the problem, and then runs sea-orm-cli generate entity on it to trigger the issue.

You need to have docker and [email protected] on the PATH for this to work.

https://gist.github.com/Patrick-Lehner-Woven-by-Toyota/811668880cf78a1bc78c679993ce137d