[SPARK-13976][SQL] do not remove sub-queries added by user when generate SQL #11786
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
|
cc @liancheng @yhuai |
|
Test build #53435 has finished for PR 11786 at commit
|
|
How about we add a before/after comparison in the description (show the difference of the generated query)? |
|
LGTM |
|
merging to master! |
This was referenced Mar 18, 2016
roygao94
pushed a commit
to roygao94/spark
that referenced
this pull request
Mar 22, 2016
…ate SQL
## What changes were proposed in this pull request?
We haven't figured out the corrected logical to add sub-queries yet, so we should not clear all sub-queries before generate SQL. This PR changed the logic to only remove sub-queries above table relation.
an example for this bug, original SQL: `SELECT a FROM (SELECT a FROM tbl) t WHERE a = 1`
before this PR, we will generate:
```
SELECT attr_1 AS a FROM
SELECT attr_1 FROM (
SELECT a AS attr_1 FROM tbl
) AS sub_q0
WHERE attr_1 = 1
```
We missed a sub-query and this SQL string is illegal.
After this PR, we will generate:
```
SELECT attr_1 AS a FROM (
SELECT attr_1 FROM (
SELECT a AS attr_1 FROM tbl
) AS sub_q0
WHERE attr_1 = 1
) AS t
```
TODO: for long term, we should find a way to add sub-queries correctly, so that arbitrary logical plans can be converted to SQL string.
## How was this patch tested?
`LogicalPlanToSQLSuite`
Author: Wenchen Fan <wenchen@databricks.com>
Closes apache#11786 from cloud-fan/bug-fix.
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Outdated suggestions cannot be applied.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 changes were proposed in this pull request?
We haven't figured out the corrected logical to add sub-queries yet, so we should not clear all sub-queries before generate SQL. This PR changed the logic to only remove sub-queries above table relation.
an example for this bug, original SQL:
SELECT a FROM (SELECT a FROM tbl) t WHERE a = 1before this PR, we will generate:
We missed a sub-query and this SQL string is illegal.
After this PR, we will generate:
TODO: for long term, we should find a way to add sub-queries correctly, so that arbitrary logical plans can be converted to SQL string.
How was this patch tested?
LogicalPlanToSQLSuite