Re: psql - add special variable to reflect the last query status

From: Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr>
To: Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
Cc: PostgreSQL Developers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: psql - add special variable to reflect the last query status
Date: 2017-06-27 15:30:51
Message-ID: alpine.DEB.2.20.1706271537220.31961@lancre
Views: Raw Message | Whole Thread | Download mbox | Resend email
Lists: pgsql-hackers

Hello Pavel,

>> We can introduce macro SetVariableBool(vars, varname, bool) instead
>> SetVariable(pset.vars, "ERROR", "FALSE");
> I checked source code, and it requires little bit more harder refactoring
> because now we have SetVariableBool - what is unhappy name, because it
> initialize variable to ON value. It is question what is better name?

The boolean values (on/off 1/0 true/false...) accepted for pg settings is
probably convenient but also somehow fuzzy.

From a programming point of view, I like booleans to have either true or
false values, and nothing else.

I agree that the existing "SetVariableBool" function is a misnommer, it
should be "SetVariableOn" given what it does, and it is not what we need.

Here is a v4 which attempts to extend & reuse the function. People might
be surprised that TRUE is used where ON was used before, so I'm not sure.

> I found more interesting issue - the code of SetResultVariables is
> partially redundant with AcceptResult - maybe the switch there can be
> shared.

I agree that there is some common structure, but ISTM that the
AcceptResult function is called in a variety of situation where variables
are not to be set (eg "internal" queries, not user provided queries), so I
thought it best to keep the two apart.


Attachment Content-Type Size
psql-result-status-4.patch text/x-diff 9.9 KB

In response to


Browse pgsql-hackers by date

  From Date Subject
Next Message Merlin Moncure 2017-06-27 15:50:51 Re: lag(bigint,int,int), etc?
Previous Message Tom Lane 2017-06-27 15:17:07 Re: CREATE COLLATION definitional questions for ICU