| From: | Kevin Grittner <kgrittn(at)ymail(dot)com> |
|---|---|
| To: | Kevin Grittner <kgrittn(at)ymail(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | Robert Haas <robertmhaas(at)gmail(dot)com>, Jeff Davis <pgsql(at)j-davis(dot)com>, Postgres-Bugs <pgsql-bugs(at)postgresql(dot)org> |
| Subject: | Re: Failure to coerce unknown type to specific type |
| Date: | 2015-05-03 19:29:55 |
| Message-ID: | 2007003193.618271.1430681395388.JavaMail.yahoo@mail.yahoo.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-bugs pgsql-hackers |
Kevin Grittner <kgrittn(at)ymail(dot)com> wrote:
> they both return NULL of type text.
Section 9.3, which the definition of COALESCE references as the
way to resolve type conflicts *starts* with this:
| Let IDTS be the set of data types specified in an application of
| this Subclause. Let DTS be the set of data types in IDTS
| excluding any data types that are undefined. If the cardinality
| of DTS is 0 (zero), then the result data type is undefined and no
| further Rules of this Subclause are evaluated.
That's pretty unambiguous that a COALESCE(NULL, NULL) clause should
yield a NULL with the data type undefined. So, if we're going by
the SQL spec, that is what it would take to conform. It's hardly a
crisis that we don't conform on this point, but it is a fact.
--
Kevin Grittner
EDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Tom Lane | 2015-05-03 19:33:51 | Re: Failure to coerce unknown type to specific type |
| Previous Message | Tom Lane | 2015-05-03 19:28:03 | Re: Failure to coerce unknown type to specific type |
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Tom Lane | 2015-05-03 19:33:51 | Re: Failure to coerce unknown type to specific type |
| Previous Message | Tom Lane | 2015-05-03 19:28:03 | Re: Failure to coerce unknown type to specific type |