Repository navigation
Fix a warning for a foreign key referencing a table with a shorter unique key - #523
Merged
JanJakes merged 1 commit intoOct 13, 2026
Conversation
…ique key When looking for the unique constraint that a foreign key references, each unique index of the referenced table is checked for having the referenced columns as a prefix. An index with fewer columns than the foreign key was read past its end, raising "Undefined array key" warnings. Skip indexes that are shorter than the column list of the reference. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
|
No actionable comments were generated in the recent review. 🎉 ℹ️ Recent review info
📝 Walkthrough
Merge Risk: ⚪ Minimal · up to The change addresses the shorter-index warning while preserving selection of the matching composite key. No actionable merge risk remains from the inspected changes. Pre-merge checks |
  |
| Check name | Status | Explanation | Resolution |
|---|---|---|---|
| Docstring Coverage |  |
Docstring coverage is 25.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 4 functions across 2 files. | Write docstrings for the functions missing them to satisfy the coverage threshold. |
✅ Passed checks (4 passed)
-
Check name Status Explanation Description Check Check skipped - CodeRabbit’s high-level summary is enabled. Title check The title clearly identifies the main change: fixing a warning caused by a foreign key referencing a shorter unique key. It is specific and concise. Linked Issues check Check skipped because no linked issues were found for this pull request. Out of Scope Changes check Check skipped because no linked issues were found for this pull request.
- Fix all pre-merge checks with AI
✨ Finishing Touches
-
🧪 Generate unit tests (beta)
-
- Create a new PR
-
- Autofix · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts
Warning
Some tools did not complete. Review the errors below.
🔧 PHPStan (2.2.14)
-
PHPStan reported 1 non-file analysis error(s); analysis is incomplete
Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.
Comment @coderabbitai help to get the list of available commands.
JanJakes
added a commit
that referenced
this pull request
Oct 14, 2026
… case (#534) ## Summary Follow-up to #523. When a foreign key references columns with a different letter case than the referenced table declares them, the referenced unique constraint is not found: ```sql CREATE TABLE t1 (id INT, name VARCHAR(255), PRIMARY KEY (id, name)); CREATE TABLE t2 (id INT, name VARCHAR(255), FOREIGN KEY (id, name) REFERENCES t1 (ID, Name)); SELECT unique_constraint_name FROM information_schema.referential_constraints WHERE table_name = 't2'; -- NULL (MySQL: PRIMARY) ``` MySQL column names are case-insensitive, but the lookup compared the referenced column names to the index columns with `!==`. The foreign key itself works, since SQLite also matches column names case-insensitively; only the information schema entry is wrong. ## Fix The names are compared case-insensitively with `strcasecmp()`, which compares them directly, without creating lowercased copies first. Identifiers are restricted to ASCII in this driver, so this is sufficient. ## Tests `testInformationSchemaForeignKeysReferencingColumnsInDifferentLetterCase` references a single-column primary key, a composite unique key, and a unique key in a foreign key added with `ALTER TABLE`, all with differently cased column names, and checks `UNIQUE_CONSTRAINT_NAME`. It fails on `trunk` with `NULL` for all three. ## Use of AI This change was prepared with Claude Code (Claude Fable 5.1). I reviewed the code, the tests, and this description, and I take responsibility for the change. 🤖 Generated with [Claude Code](https://claude.com/claude-code) <!-- This is an auto-generated comment: release notes by coderabbit.ai --> ## Summary by CodeRabbit * **Bug Fixes** * Foreign-key metadata now correctly matches referenced columns when their names use different letter casing. This applies to single-column and composite references, whether constraints are defined during table creation or added afterward. * Information schema results now identify the expected unique indexes for these foreign-key references, including primary-key references. <!-- end of auto-generated comment: release notes by coderabbit.ai --> --------- Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com> Co-authored-by: Jan Jakeš <jan@jakes.pro>
This file contains hidden or 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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
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.
Summary
Creating a multi-column foreign key raises
Undefined array key 1warnings when the referenced table also has a unique key with fewer columns:When looking for the unique constraint a foreign key references, each unique index of the referenced table is checked for having the referenced columns as a prefix. A shorter index is read past its end. The resulting
UNIQUE_CONSTRAINT_NAMEis still correct, but the warning is emitted, and underWP_DEBUGit is printed into the page.Fix
Indexes with fewer columns than the reference are skipped, since they cannot have the referenced columns as a prefix.
Tests
testInformationSchemaForeignKeysReferencingShorterUniqueKeychecks that the statement succeeds without a warning and thatREFERENTIAL_CONSTRAINTS.UNIQUE_CONSTRAINT_NAMEis the longer key. It fails ontrunkwith the warning (PHPUnit converts warnings to exceptions).packages/mysql-on-sqlite: 1044 tests pass (PHP 8.3, SQLite 3.45.1); PHPCS is clean.Found while running WooCommerce on WordPress Playground.
Use of AI
This change was prepared with Claude Code (Claude Fable 5.1). I reviewed the code, the tests, and this description, and I take responsibility for the change.
🤖 Generated with Claude Code
Summary by CodeRabbit