[SPARK-25736][SQL][TEST] add tests to verify the behavior of multi-column count #22728
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this is indeed the behavior I'd expect. Good to add tests to enforce the behavior. Did you check other RDBMs apart from Postgres? |
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I'm going to try Hive and Presto, but my local environment has some problems and I need to fix it first. Will work on it tomorrow. |
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BTW MySQL doesn't support |
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Yea, it is definitely good to add document and test for current behavior. |
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Test build #97401 has finished for PR 22728 at commit
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Test build #97400 has finished for PR 22728 at commit
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| FROM testData; | ||
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| -- count with multiple expressions | ||
| SELECT count(a, b), count(b, a), count(testData.*) FROM testData; |
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Please also include count(*)
| SELECT count(a, b), count(b, a), count(testData.*) FROM testData; | ||
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| -- distinct count with multiple expressions | ||
| SELECT count(DISTINCT a, b), count(DISTINCT b, a), count(DISTINCT testData.*) FROM testData; |
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Also include count(DISTINCT *)
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Let us add one more case in the test suite. SELECT count(1), count(NULL) FROM testData; |
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LGTM except the above comments. |
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LGTM |
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Test build #97420 has finished for PR 22728 at commit
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Merged to master and branch-2.4. |
…lumn count ## What changes were proposed in this pull request? AFAIK multi-column count is not widely supported by the mainstream databases(postgres doesn't support), and the SQL standard doesn't define it clearly, as near as I can tell. Since Spark supports it, we should clearly document the current behavior and add tests to verify it. ## How was this patch tested? N/A Closes #22728 from cloud-fan/doc. Authored-by: Wenchen Fan <wenchen@databricks.com> Signed-off-by: hyukjinkwon <gurwls223@apache.org> (cherry picked from commit e028fd3) Signed-off-by: hyukjinkwon <gurwls223@apache.org>
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FYI, I tried both hive and presto, neither of them supports multi-column count. |
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thanks for your work @cloud-fan ! |
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(From #22773 (comment)) @gatorsmile and @cloud-fan, let's say this will break |
…lumn count ## What changes were proposed in this pull request? AFAIK multi-column count is not widely supported by the mainstream databases(postgres doesn't support), and the SQL standard doesn't define it clearly, as near as I can tell. Since Spark supports it, we should clearly document the current behavior and add tests to verify it. ## How was this patch tested? N/A Closes apache#22728 from cloud-fan/doc. Authored-by: Wenchen Fan <wenchen@databricks.com> Signed-off-by: hyukjinkwon <gurwls223@apache.org>
6 participants
What changes were proposed in this pull request?
AFAIK multi-column count is not widely supported by the mainstream databases(postgres doesn't support), and the SQL standard doesn't define it clearly, as near as I can tell.
Since Spark supports it, we should clearly document the current behavior and add tests to verify it.
How was this patch tested?
N/A