[SPARK-31753] Add missing keywords in the SQL documents

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.0.1, 3.1.0
• Fix Version/s: 3.0.1
• Component/s: Documentation, SQL
• Assignee: philipse
• Reporter: Takeshi Yamamuro
• Created: 19/May/20 03:02
• Updated: 27/Sep/20 14:05
• Resolved: 28/Jul/20 00:49

Description

Some keywords are missing in the SQL documents and a list of them is as follows. 
https://github.com/apache/spark/pull/28290#issuecomment-619321301

AFTER
CASE/ELSE
WHEN/THEN
IGNORE NULLS
LATERAL VIEW (OUTER)?
MAP KEYS TERMINATED BY
NULL DEFINED AS
LINES TERMINATED BY
ESCAPED BY
COLLECTION ITEMS TERMINATED BY
EXPLAIN LOGICAL
PIVOT

They should be documented there, too.

Issue Links

• links to: [Github] Pull Request #29056 (GuoPhilipse)
• links to: [Github] Pull Request #29056 (GuoPhilipse)
• links to: [Github] Pull Request #29883 (GuoPhilipse)
• links to: [Github] Pull Request #29883 (GuoPhilipse)