Add COUNT DISTINCT Rewriter #20
Open
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
kaikalur
suggested changes
Apr 8, 2021
| private boolean isUsingCountDistinctComparisonToCheckUniqueness(Comparison node) | ||
| { | ||
| Optional<AstNode> aggregationFunction = Optional.ofNullable(node.GetFirstChildOfKind(JJTAGGREGATIONFUNCTION)); | ||
| return aggregationFunction.isPresent() && aggregationHasCountDistinct((AggregationFunction) aggregationFunction.get()) && secondArgIsLiteralOne(node); |
There was a problem hiding this comment.
We need to enhance the AST attributes to remember the operator. It's a TODO(viswanadha) :)
There was a problem hiding this comment.
Oops. I forgot I had the correct definition in the doc. So deleting these comments lol
| private boolean aggregationHasCountDistinct(AggregationFunction node) | ||
| { | ||
| Optional<AstNode> setQuantifier = Optional.ofNullable(node.GetFirstChildOfKind(JJTSETQUANTIFIER)); | ||
| return setQuantifier.isPresent() && node.beginToken.image.equalsIgnoreCase("COUNT") && unparse(setQuantifier.get()).equalsIgnoreCase("DISTINCT"); |
There was a problem hiding this comment.
setQuantifier is a leaf node so you can just get the image and check. We will redo this to make it an in attribute so we can just check the token.
kaikalur
reviewed
Apr 8, 2021
| private boolean isUsingCountDistinctComparisonToCheckUniqueness(Comparison node) | ||
| { | ||
| Optional<AstNode> aggregationFunction = Optional.ofNullable(node.GetFirstChildOfKind(JJTAGGREGATIONFUNCTION)); | ||
| return aggregationFunction.isPresent() && aggregationHasCountDistinct((AggregationFunction) aggregationFunction.get()) && secondArgIsLiteralOne(node); |
There was a problem hiding this comment.
We need to enhance the AST attributes to remember the operator. It's a TODO(viswanadha) :)
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.
Added a rewriter for the following anti-pattern:
-> Uses "COUNT(DISTINCT x) > 1" to check for duplicates