[SPARK-21136] Misleading error message for typo in SQL

• Type: Sub-task
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.1.0
• Component/s: SQL
• Assignee: Yesheng Ma
• Reporter: Daniel Darabos
• Created: 19/Jun/17 07:58
• Updated: 12/Jun/19 01:38
• Resolved: 12/Jun/19 01:38

Description

scala> spark.sql("select * from a left joinn b on a.id = b.id").show
org.apache.spark.sql.catalyst.parser.ParseException:
mismatched input 'from' expecting {<EOF>, 'WHERE', 'GROUP', 'ORDER', 'HAVING', 'LIMIT', 'LATERAL', 'WINDOW', 'UNION', 'EXCEPT', 'MINUS', 'INTERSECT', 'SORT', 'CLUSTER', 'DISTRIBUTE'}(line 1, pos 9)

== SQL ==
select * from a left joinn b on a.id = b.id
---------^^^

The issue is that ^^^ points at from, not at joinn. The text of the error makes no sense either. If *, a, and b are complex in themselves, a misleading error like this can hinder debugging substantially.

I tried to see if maybe I could fix this. Am I correct to deduce that the error message originates in ANTLR4, which parses the query based on the syntax defined in SqlBase.g4? If so, I guess I would have to figure out how that syntax definition works, and why it misattributes the error.

Issue Links

• links to: GitHub Pull Request #24809