You can check the below doc of SqlValidatorUtil#getAlias for explanation:
/**
* Derives an alias for a node, and invents a mangled identifier if it
* cannot.
*
* Examples:
*
*
* Alias: "1 + 2 as foo" yields "foo"
* Identifier: "foo.bar.baz" yields "baz"
* Anything
That means Calcite can only return real columnName or columnLabel from simple
column or alias. And any aggregate function, or calculate expression without
alias, parsing expression, i.e, `EXPR$0` will be returned?
Juan Pan
panj...@apache.org
Juan Pan(Trista), Apache ShardingSphere
On
If no column name given explicitly, e.g. by alias or simple identifier,
Calcite will derive one but not from the aggregate function.
Juan Pan 于2019年9月29日周日 下午1:12写道：
> Thank for your reply. It is a indirect way to get columnName.
>
>
> Calcite can not return the real columnName from SQL, is it
Thank for your reply. It is a indirect way to get columnName.
Calcite can not return the real columnName from SQL, is it right?
Juan Pan
panj...@apache.org
Juan Pan(Trista), Apache ShardingSphere
On 09/29/2019 12:21，XING JIN wrote：
You can try to give an alias for the selected column.
You can try to give an alias for the selected column.
Juan Pan 于2019年9月29日周日 上午11:39写道：
>
>
> Hi everyone,
>
>
> I executed SQL `select count(*) from tb1` through Calcite and
> resultSet.getMetaData().getColumnName(i) in my project. But the result is
> `EXPR$0` not `COUNT(*)`.
>
>
> Is there
Hi everyone,
I executed SQL `select count(*) from tb1` through Calcite and
resultSet.getMetaData().getColumnName(i) in my project. But the result is
`EXPR$0` not `COUNT(*)`.
Is there any way to get real columnName?
Thanks for your attention.
Regard,
Trista
Juan Pan
