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Unexpected null equality

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#269 15 comments 0 reactions 0 assignees View on GitHub

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Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
30/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
scala, sql
Domain
data, testing

Research direction

Start in dataset/src/test/scala/frameless/FilterTests.scala at lines 132-133 and inspect the existing filter and equality tests. Trace the behavior under test and compare it with the SQL NULL semantics described in the issue; done means the tests and implementation agree on the intended null equality behavior.

Written by the indexing model from the issue text.

Description

bug help wanted

In SQL

SELECT NULL = NULL;

results in NULL, which is a falsy value when used in WHERE, so eg.

SELECT 1 WHERE NULL = NULL

returns an empty table.

However in Scala, both null == null and None == None are true.

Consequently these two lines should not pass.

Dominant language
Scala
Stars
895
Forks
135
Avg merge
1d 16h
Merged PRs (30d)
3

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