Re: proposal - assign result of query to psql variable - Mailing list pgsql-hackers

From Shigeru Hanada
Subject Re: proposal - assign result of query to psql variable
Date
Msg-id CAEZqfEdUmCiHOfcwO82Y4iTKvPG0F1Jz_6xitj=N4q8_pNt7Mw@mail.gmail.com
Whole thread Raw
In response to Re: proposal - assign result of query to psql variable  (Pavel Stehule <pavel.stehule@gmail.com>)
Responses Re: proposal - assign result of query to psql variable  (Pavel Stehule <pavel.stehule@gmail.com>)
Re: proposal - assign result of query to psql variable  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Sat, Feb 2, 2013 at 7:30 PM, Pavel Stehule <pavel.stehule@gmail.com> wrote:
> possible variants
>
> a) don't store NULL  values - and remove existing variable when NULL
> be assigned - it is probably best, but should be confusing for users
> b) implement flag IS NULL - for variables
> c) use nullPrint
> d) use empty String

+1 for a).  If users want to determine whether the result was NULL, or
want to use substitute string for NULL result, they can use coalesce
in SELECT clause.  Anyway the feature should be documented clearly.

-- 
Shigeru HANADA



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