[DRILL-8222] Wrong function's implementation of concat_delim

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.20.1
• Fix Version/s: 1.21.0
• Component/s: Functions - Drill
• Assignee: Unassigned
• Reporter: Xurenhe
• Created: 11/May/22 11:07
• Updated: 15/Aug/23 11:35
• Resolved: 15/Aug/23 11:35

Description

Current function implementation of `concat_delim` is wrong.

select concat_delim(',', 'a', null, 'b') as c 

We may want the result of 'a,b', which ignore null value during executing.

 

But, actual result is 'a,,b'.
I found the similar function(concat_ws) in MySQL and Postgres, and the behavior is what I wish.

 

---

 

@Test
public void testConcatDelimVarArgsWithNullValue() throws Exception {
  testBuilder()
    .sqlQuery("select concat_delim(',', 'a', null, 'b') as c")
    .unOrdered()
    .baselineColumns("c")
    .baselineValues("a,b")
    .go();
}