[SPARK-13698][SQL] Fix Analysis Exceptions when Using Backticks in Generate

[dilipbiswal]

What changes were proposed in this pull request?

Analysis exception occurs while running the following query.

SELECT ints FROM nestedArray LATERAL VIEW explode(a.b) `a` AS `ints`

Failed to analyze query: org.apache.spark.sql.AnalysisException: cannot resolve '`ints`' given input columns: [a, `ints`]; line 1 pos 7
'Project ['ints]
+- Generate explode(a#0.b), true, false, Some(a), [`ints`#8]
   +- SubqueryAlias nestedarray
      +- LocalRelation [a#0], [[[[1,2,3]]]]

How was this patch tested?

Added new unit tests in SQLQuerySuite and HiveQlSuite

[dilipbiswal]

cc @liancheng @gatorsmile

[liancheng]

ok to test

[liancheng]

This change itself LGTM. However, the current implementation of cleanIdentifier doesn't handle escaped back-ticks within identifier names, e.g. weirdname``. (Back-ticks within identifiers are escaped by double-back-ticks.) But we can address this issue in another PR.

[SparkQA]

Test build #52516 has finished for PR 11538 at commit 385f6d4.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[dilipbiswal]

@liancheng Thanks a lot. I will work on the follow up PR to handle escaped back-ticks.

[cloud-fan]

hi @dilipbiswal , can you update your test case to use escaped back-ticks(e.g. weirdname``)? I think it's already handled by ANTLR.

[dilipbiswal]

Hi @cloud-fan Sure.. will do.

[SparkQA]

Test build #52655 has finished for PR 11538 at commit 07af901.

• This patch fails Scala style tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #52660 has finished for PR 11538 at commit ba6411a.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[cloud-fan]

nit: please follow the code style of other tests, e.g. https://github.com/dilipbiswal/spark/blob/SPARK-13698/sql/hive/src/test/scala/org/apache/spark/sql/hive/HiveQlSuite.scala#L195-L199

[cloud-fan]

LGTM except one style comment

[SparkQA]

Test build #52712 has finished for PR 11538 at commit 7ed8ef7.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[cloud-fan]

LGTM cc @liancheng

[cloud-fan]

thanks, merging to master!