feat: add single_value agg function #824
Merged
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
TennyZhuang
approved these changes
Mar 10, 2022
liurenjie1024
approved these changes
Mar 10, 2022
Codecov Report
@@ Coverage Diff @@
## main #824 +/- ##
============================================
+ Coverage 72.22% 72.24% +0.01%
Complexity 2766 2766
============================================
Files 923 923
Lines 53652 53700 +48
Branches 1787 1787
============================================
+ Hits 38752 38796 +44
- Misses 14010 14014 +4
Partials 890 890
Flags with carried forward coverage won't be shown. Click here to find out more.
Continue to review full report at Codecov.
|
2 tasks
xiangjinwu
reviewed
Mar 10, 2022
Comment on lines
+91
to
+92
| (None, _) => Ok(input), | ||
| (Some(_), None) => Ok(result), |
Contributor
There was a problem hiding this comment.
Seems a column with [None, Some(2), None] would return Ok rather than Err? It is an error in pg.
btw, how does it work in 2-phase agg?
Contributor
Author
There was a problem hiding this comment.
Good catch!
I believe these two mistakes that need to be corrected. Let me track both points in a new 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Outdated suggestions cannot be applied.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.
What's changed and what's your intention?
PLEASE DO NOT LEAVE THIS EMPTY !!!
This PR adds a special
single_valueaggregation function as defined in Calcite.Its appearance is due to scalar subquery. Scalar subquery, such as in
select .... from .... where column X = (select column Y from ......), should only return one row.
single_valueaggregation function would check whether the subquery indeed returns exactly one row. The different behaviors from general aggregation functions is:pub fn single_value<'a, T>(result: Option<T>, input: Option<T>) -> Option<T>now needs to return aresultas it cannot acceptSometwice.Based on the observation of PG, it does not really error when there is no row returned. So we don't need to change
output_concrete.Haven't added tests yet.
Checklist