[ 
https://issues.apache.org/jira/browse/CALCITE-4999?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17531197#comment-17531197
 ] 

Dmitry Sysolyatin edited comment on CALCITE-4999 at 5/3/22 1:33 PM:
--------------------------------------------------------------------

[~julianhyde] 
Ok, I will think about it. But changing constructors is not so bad idea for me. 
Assume that someone implements Collect interface and updates calcite version 
then his/her implementation will fail in runtime in case of subquery. Runtime 
error is more dangerous than compile error


was (Author: dmsysolyatin):
[~julianhyde] 
Ok, I will think about it. But changing constructors is not so bad idea for me. 
Assume that someone implements Collect class and updates calcite version then 
his/her implementation will fail in runtime in case of subquery. Runtime error 
is more dangerous than compile error

> ARRAY function should return an array of scalars if subquery returns 1 column
> -----------------------------------------------------------------------------
>
>                 Key: CALCITE-4999
>                 URL: https://issues.apache.org/jira/browse/CALCITE-4999
>             Project: Calcite
>          Issue Type: Bug
>          Components: core
>            Reporter: Dmitry Sysolyatin
>            Assignee: Dmitry Sysolyatin
>            Priority: Major
>              Labels: pull-request-available
>          Time Spent: 0.5h
>  Remaining Estimate: 0h
>
> At the moment `array` function returns [RecordType ARRAY] if subquery is 
> passed like an argument.
> {code:java}
> SELECT array(select 'toast.' || x from unnest(ARRAY['1','2']) x){code}
> But Sql standard says:
> {code:java}
> 6.38 <array value constructor>
> Function
> Specify construction of an array.
> Format
> <array value constructor> ::=
> <array value constructor by enumeration>
> | <array value constructor by query>
> [...]
> <array value constructor by query> ::=
> ARRAY <table subquery>
> Syntax Rules
> [...]
> 3) If <array value constructor by query> is specified, then
> a) The <query expression> QE simply contained in the <table subquery> shall 
> be of degree 1 (one). Let ET be the declared type of the column in the result 
> of <query expression>.
> b) The declared type of the <array value constructor by query> is array with 
> element type ET and maximum cardinality equal to the implementation-defined 
> maximum cardinality IMDC for such array types.
> {code}
> Proposed solution is to return an array of scalars (e.g. INTEGER ARRAY) when 
> the query returns 1 column, and continue to return an array of ROW when the 
> query has 2 or more columns. And do the same for MULTISET.



--
This message was sent by Atlassian Jira
(v8.20.7#820007)

Reply via email to