[6.0-rc2] Query: Translate ToList over grouping element

[smitpatel]

Part 2 & 3 of #26046

Description

• Query with GroupBy as final operator throws unfriendly error message
• Query which specifies ToList over grouping element throws translation error or generate incorrect results

Customer Impact
Customer will get exception thrown or incorrect results

How found
Manual testing done by @ajcvickers

Test coverage
Added regression tests for scenario and similar cases.

Regression?

• Query with GroupBy as final operator throwing unfriendly error message is a regression (we used to throw better message)
• Query with ToList over grouping element is a new feature in 6.0

Risk

• Low. Code change is minimal and we have many tests going over same code path.

[smitpatel]

This API was changed in 6.0, now it goes back to what it was in 5.0

[smitpatel]

This was new API in 6.0

[AndriySvyryd]

🐑 🇮🇹

[smitpatel]

@Pilchie @dotnet/efteam - This needs to be merged to rc2 branch. Need approval.

This couldn't finish in time because helix/windows builds are timing out.

[ajcvickers]

@smitpatel Please fill out the servicing template above.

[ajcvickers]

/azp run

[azure-pipelines]

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[smitpatel]

Filled in template.

[Pilchie]

This introduces RC1 -> RC2 breaking API changes, right? Do we have a communication plan for those?

[smitpatel]

The API being changed above are public mainly for providers. No customer should be using it in normal course of action. Further, even with the change, most of the work is done by relational provider itself without providers having to write a code which uses that API. There are only handful of providers which would have upgraded upto rc1 packages at this point. Perhaps we can just tag in the post to communicate?

[ajcvickers]

@smitpatel Can we verify that our major external providers for MySQL (@lauxjpn) and ProsgreSQL (@roji) will not break going from RC1 to RC2? This well help ensure people can quickly adopt RC2 when it goes out.

[smitpatel]

MySql doesn't have rc1 package yet.
My github search skills indicated that efcore.pg is not using any of above 2 APIs. @roji can provider better confirmation.

[Pilchie]

Okay, I'll approve based on that. Can we warn the MySQL author that this is coming in case they make an RC1 package between now and when RC2 releases?

[roji]

All OK from my side (efcore.pg).

[smitpatel]

@lauxjpn - If you are releasing package for rc1, please let me know if you need to use any of the API above. I can provide a work-around. (perhaps add them in future release if they are needed by providers).

[lauxjpn]

@lauxjpn - If you are releasing package for rc1, please let me know if you need to use any of the API above. I can provide a work-around. (perhaps add them in future release if they are needed by providers).

@smitpatel Thanks, should not be an issue for us.