Fix to #35108 - Temporal table migration regression from EF Core 8 to 9 #35283
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
There was a problem hiding this comment.
Copilot reviewed 2 out of 2 changed files in this pull request and generated no suggestions.
AndriySvyryd
reviewed
Dec 7, 2024
src/EFCore.SqlServer/Migrations/SqlServerMigrationsSqlGenerator.cs
Outdated
Show resolved
Hide resolved
AndriySvyryd
reviewed
Dec 7, 2024
| case AlterColumnOperation alterColumnOperation: | ||
| RemoveLegacyTemporalColumnAnnotations(alterColumnOperation); | ||
| RemoveLegacyTemporalColumnAnnotations(alterColumnOperation.OldColumn); | ||
| if (!CanSkipAlterColumnOperation(alterColumnOperation, alterColumnOperation.OldColumn)) |
There was a problem hiding this comment.
To be safe only call this if any annotations were removed
There was a problem hiding this comment.
it's already the case - we short-circuit all operations that don't contain SqlServerAnnotationNames.IsTemporal set to true. For AlterColumnOperation (actually all column operations) IsTemporal is only set for legacy scenario
AndriySvyryd
reviewed
Dec 7, 2024
src/EFCore.SqlServer/Migrations/SqlServerMigrationsSqlGenerator.cs
Outdated
Show resolved
Hide resolved
AndriySvyryd
reviewed
Dec 7, 2024
src/EFCore.SqlServer/Migrations/SqlServerMigrationsSqlGenerator.cs
Outdated
Show resolved
Hide resolved
AndriySvyryd
reviewed
Dec 7, 2024
src/EFCore.SqlServer/Migrations/SqlServerMigrationsSqlGenerator.cs
Outdated
Show resolved
Hide resolved
AndriySvyryd
reviewed
Dec 7, 2024
AndriySvyryd
approved these changes
Dec 7, 2024
In 9 we changed the way we process migration of temporal tables. One of the changes was drastically reducing the number of annotations for columns which are part of temporal tables. This however caused regressions for cases where migration code was created using EF8 (and containing those legacy annotations) but then executed using EF9 tooling. Specifically, extra annotations were generating a number of superfluous Alter Column operations (which were only modifying those annotations). In EF8 we had logic to weed out those operations, but it was removed in EF9. Fix is to remove all the legacy annotations on column operations before we start processing them. We no longer rely on them, but rather use annotations on Table operations and/or relational model. The only exception is CreateColumnOperation, so for it we convert old annotations to TemporalIsPeriodStartColumn and TemporalIsPeriodEndColumn where appropriate. Also, we are bringing back logic from EF8 which removed unnecessary AlterColumnOperations if the old and new columns are the same after the legacy temporal annotations have been removed. Fixes #35108 Also fixes #35148 which was the same underlying issue.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
In 9 we changed the way we process migration of temporal tables. One of the changes was drastically reducing the number of annotations for columns which are part of temporal tables. This however caused regressions for cases where migration code was created using EF8 (and containing those legacy annotations) but then executed using EF9 tooling. Specifically, extra annotations were generating a number of superfluous Alter Column operations (which were only modifying those annotations). In EF8 we had logic to weed out those operations, but it was removed in EF9.
Fix is to remove all the legacy annotations on column operations before we start processing them. We no longer rely on them, but rather use annotations on Table operations and/or relational model. The only exception is CreateColumnOperation, so for it we convert old annotations to TemporalIsPeriodStartColumn and TemporalIsPeriodEndColumn where appropriate. Also, we are bringing back logic from EF8 which removed unnecessary AlterColumnOperations if the old and new columns are the same after the legacy temporal annotations have been removed.
Fixes #35108
Also fixes #35148 which was the same underlying issue.