Fix issue 1219 - MERGE not seeing previous clause var (#1441) #1444
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
Fixed issue 1219 where MERGE did not see the previous clause's
variable.
This description is a bit misleading as the transform phase did see
the variable and was able to use it. However, the planner phase
removed the variable by replacing it with a NULL Const. This caused
MERGE to see a NULL Const for the previous tuple, generating
incorrect results. However, this only occurred for very specific
cases.
Fx: MATCH (x) MERGE (y {id: id(x)}) -- worked
MATCH (x) MERGE (y {id: id(x)}) RETURN y -- didn't
MATCH (x) MERGE (y {id: id(x)}) RETURN x, y -- worked
The change impacted no current regression tests and involved wrapping
all explicitly defined variables' target entries with a volatile
wrapper.
Added new regression tests.
rafsun42
approved these changes
Dec 11, 2023
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Outdated suggestions cannot be applied.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.
Fixed issue 1219 where MERGE did not see the previous clause's variable.
This description is a bit misleading as the transform phase did see the variable and was able to use it. However, the planner phase removed the variable by replacing it with a NULL Const. This caused MERGE to see a NULL Const for the previous tuple, generating incorrect results. However, this only occurred for very specific cases.
Fx: MATCH (x) MERGE (y {id: id(x)}) -- worked
MATCH (x) MERGE (y {id: id(x)}) RETURN y -- didn't
MATCH (x) MERGE (y {id: id(x)}) RETURN x, y -- worked
The change impacted no current regression tests and involved wrapping all explicitly defined variables' target entries with a volatile wrapper.
Added new regression tests.