why can't i use `SUM0` in flink sql?
# troubleshootings
slowratatoskr
06/12/2023, 2:58 PMwhy can't i use
SUM0m
Martijn Visser
06/12/2023, 2:59 PM Copy code
select sum(0); Copy code
EXPR$0
0Martijn Visser
06/12/2023, 2:59 PMWorks here
s
slowratatoskr
06/12/2023, 2:59 PMNo, i mean sum0
slowratatoskr
06/12/2023, 3:00 PMIf all values are null, 0 is returned
m
Martijn Visser
06/12/2023, 3:01 PMDo you have an example?
Martijn Visser
06/12/2023, 3:01 PMBecause
sum0Martijn Visser
06/12/2023, 3:01 PMIf a value is null, there's nothing to sum because null is not an integer.
s
slowratatoskr
06/12/2023, 3:02 PMslowratatoskr
06/12/2023, 3:03 PMUnder aggregate functions section
m
Martijn Visser
06/12/2023, 3:03 PMThat's not an example, but it's a reference π
Martijn Visser
06/12/2023, 3:03 PMWhat is the SQL syntax you're trying to execute?
s
slowratatoskr
06/12/2023, 3:03 PMWhy is it N/A
m
Martijn Visser
06/12/2023, 3:03 PMThere's no equivalent for it in the SQL syntax
s
slowratatoskr
06/12/2023, 3:04 PMI don't get it it's already part of the table api
m
Martijn Visser
06/12/2023, 3:04 PMTable API is Flink's own definition, but for SQL we rely on the ANSI SQL Standard
Martijn Visser
06/12/2023, 3:04 PMAnd there's no "sum0" function on the ANSI Sql Standard
s
slowratatoskr
06/12/2023, 3:05 PMIf i want to ise it, i need a udf?
slowratatoskr
06/12/2023, 3:05 PMuse*
m
Martijn Visser
06/12/2023, 3:05 PMYes
s
slowratatoskr
06/12/2023, 3:07 PMI can use this as a default implem right
https://nightlies.apache.org/flink/flink-docs-stable/api/java/org/apache/flink/table/planner/functions/aggfunctions/Sum0AggFunction.html
m
Martijn Visser
06/12/2023, 3:08 PMMost likely yes