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

From Tom Lane
Subject Re: proposal - assign result of query to psql variable
Date
Msg-id 19302.1359826709@sss.pgh.pa.us
Whole thread Raw
In response to Re: proposal - assign result of query to psql variable  (Shigeru Hanada <shigeru.hanada@gmail.com>)
Responses Re: proposal - assign result of query to psql variable
Re: proposal - assign result of query to psql variable
List pgsql-hackers
Shigeru Hanada <shigeru.hanada@gmail.com> writes:
> 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.

Yeah, I was considering that one too.  Let's do it that way.
        regards, tom lane



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