[DRILL-4366] case expression referencing columns[..] = literal fails to resolve to tru

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.4.0
• Component/s: SQL Parser
• Assignee: Unassigned
• Reporter: N Campbell
• Created: 07/Feb/16 18:51
• Updated: 07/Feb/16 23:30

Description

A file (i.e PSV) has one or more columns with the string literal \N. A query that projects a conditional value based on testing the columns[N] being equal never results in true. Meanwhile comparing the same literal to the result of a substring applied to the same column works.

SELECT columns[0] as RNUM, columns[1], case when substr(columns[1],1,2)= '\N' then 1 else 0 end ,case when columns[1]='\N' then 1 else 0 end FROM `dfs`.`TEXT`.`./TBINT.tbl` LIMIT 100

input file TBINT.tbl

0|\N
1|-1
2|0
3|1
4|10