[SQL] Forbid negation when applied to unsigned values #5397
Conversation
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
Signed-off-by: Mihai Budiu <[email protected]>
Contributor
There was a problem hiding this comment.
Pull request overview
This pull request adds validation to prevent the unary minus (negation) operator from being applied to unsigned integer values, fixing issues #5386 and #5385. The change correctly identifies that negating an unsigned value is semantically invalid and could lead to unexpected behavior.
Key changes:
- Added compile-time validation that throws an error when unary minus is applied to unsigned integers
- Added regression tests to verify the validation works correctly
- Updated documentation to clarify that unary minus cannot be applied to unsigned values
Reviewed changes
Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.
| File | Description |
|---|---|
| sql-to-dbsp-compiler/SQL-compiler/src/main/java/org/dbsp/sqlCompiler/compiler/frontend/ExpressionCompiler.java | Added validation logic to reject unary minus on unsigned integer types during compilation |
| sql-to-dbsp-compiler/SQL-compiler/src/test/java/org/dbsp/sqlCompiler/compiler/sql/simple/Regression1Tests.java | Added test cases to verify compilation fails with appropriate error message when negating unsigned integers |
| docs.feldera.com/docs/sql/integer.md | Updated documentation to explicitly state that unary minus cannot be applied to unsigned values |
Comment on lines
+1722
to
+1730
| public void issue5386() { | ||
| this.statementsFailingInCompilation(""" | ||
| CREATE TABLE T(x INT UNSIGNED); | ||
| CREATE VIEW V AS SELECT -x FROM T;""", | ||
| "Unary minus cannot be applied"); | ||
| this.statementsFailingInCompilation( | ||
| "CREATE VIEW V AS SELECT - CAST(1 AS INT UNSIGNED)", | ||
| "Unary minus cannot be applied"); | ||
| } |
There was a problem hiding this comment.
The test coverage for unsigned negation is limited to only INT UNSIGNED. Consider adding test cases for other unsigned integer types: TINYINT UNSIGNED, SMALLINT UNSIGNED, and BIGINT UNSIGNED to ensure the validation works consistently across all unsigned integer types.
rivudhk
approved these changes
Jan 9, 2026
github-merge-queue
bot
removed this pull request from the merge queue due to failed status checks
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.
Fixes #5386
Fixes #5385