[
https://issues.apache.org/jira/browse/FLINK-20578?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17433476#comment-17433476
]
Saad Ur Rahman edited comment on FLINK-20578 at 10/24/21, 10:38 PM:
--------------------------------------------------------------------
As I understand the problem we would need to override
[SqlMultisetValueConstructor.checkOperandTypes|https://github.com/apache/calcite/blob/77bb696d020bea4467151109ffed4ced53ff0c2d/core/src/main/java/org/apache/calcite/sql/fun/SqlMultisetValueConstructor.java#L87]
in
[SqlArrayConstructor|https://github.com/apache/flink/blob/2cb477343de5dce70978c0add5ec58edbaec157c/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/functions/sql/SqlArrayConstructor.java#L33]
My solution would be to perform a check in the overridden
_SqlArrayConstructor.checkOperandTypes_ for empty _argTypes_, pack the
_callBinding_ with a value and pass it to the _super.checkOperandTypes_ to
process it as it would before. The reason I want to pack it with a value is
that there was a reason why an empty _argTypes_ was supposed to originally
throw an error.
Then the question becomes that which [~pensz] raised: what [argument
type|https://ci.apache.org/projects/flink/flink-docs-release-1.13/docs/dev/table/types/#constructured-data-types]
should be used?
If all you would like to do is suppress the error then something like this
would probably suffice in
[SqlArrayConstructor|https://github.com/apache/flink/blob/2cb477343de5dce70978c0add5ec58edbaec157c/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/functions/sql/SqlArrayConstructor.java#L33]:
{noformat}
@Override
public boolean checkOperandTypes(SqlCallBinding callBinding, boolean
throwOnFailure) {
try {
return super.checkOperandTypes(callBinding, throwOnFailure);
} catch (CalciteException e) {
if (e.getMessage().equals(RESOURCE.requireAtLeastOneArg())) {
return true;
}
throw e;
}
}{noformat}
was (Author: surahman):
As I understand the problem we would need to override
[SqlMultisetValueConstructor.checkOperandTypes|https://github.com/apache/calcite/blob/77bb696d020bea4467151109ffed4ced53ff0c2d/core/src/main/java/org/apache/calcite/sql/fun/SqlMultisetValueConstructor.java#L87]
in
[SqlArrayConstructor|https://github.com/apache/flink/blob/2cb477343de5dce70978c0add5ec58edbaec157c/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/functions/sql/SqlArrayConstructor.java#L33]
My solution would be to perform a check in the overridden
_SqlArrayConstructor.checkOperandTypes_ for empty _argTypes_, pack the
_callBinding_ with a value and pass it to the _super.checkOperandTypes_ to
process it as it would before. The reason I want to pack it with a value is
that there was a reason why an empty _argTypes_ was supposed to originally
throw an error.
Then the question becomes that which [~pensz] raised: what [argument
type|https://ci.apache.org/projects/flink/flink-docs-release-1.13/docs/dev/table/types/#constructured-data-types]
should be used?
> Cannot create empty array using ARRAY[]
> ---------------------------------------
>
> Key: FLINK-20578
> URL: https://issues.apache.org/jira/browse/FLINK-20578
> Project: Flink
> Issue Type: Sub-task
> Components: Table SQL / API
> Affects Versions: 1.11.2
> Reporter: Fabian Hueske
> Priority: Major
> Labels: starter
> Fix For: 1.15.0
>
>
> Calling the ARRAY function without an element (`ARRAY[]`) results in an error
> message.
> Is that the expected behavior?
> How can users create empty arrays?
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
