| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Wood May <asdf_pg(at)outlook(dot)com> |
| Cc: | "pgsql-hackers(at)lists(dot)postgresql(dot)org" <pgsql-hackers(at)lists(dot)postgresql(dot)org> |
| Subject: | Re: Reference column alias for common expressions |
| Date: | 2022-05-24 16:03:42 |
| Message-ID: | 1651063.1653408222@sss.pgh.pa.us |
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| Lists: | pgsql-hackers |
Wood May <asdf_pg(at)outlook(dot)com> writes:
> Some databases (like Teradata) support the following syntax:
> select col1, col2*20 as col2_1, col2_1*200 as col3_1 from your_table;
> The last element in the target list can refer the second one using its alias.
> This feature is similar to some programming languages (like Lisp)'s let*.
> For Postgres, it seems the only way is to write a subquery and then a new target list.
> Will Postgres plan to support this feature?
No. It's flat out contrary to the SQL standard.
regards, tom lane
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