Tag: variables

Waiting for 9.3 – Create a psql command \gset to store query results into psql variables

On 2nd of February, Tom Lane committed patch:

Create a psql command \gset to store query results into psql variables.
 
This eases manipulation of query results in psql scripts.
 
Pavel Stehule, reviewed by Piyush Newe, Shigeru Hanada, and Tom Lane

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Waiting for 8.5 – PL/pgSQL variable resolution

On 13th of November (I know, backlog again), Tom Lane committed patch which make PostgreSQL more strict about what happens in stored procedures in PL/pgSQL:

ADD control knobs FOR plpgsql's variable resolution behavior, and make the
default be "throw error on conflict", as per discussions.  The GUC variable
is plpgsql.variable_conflict, with values "error", "use_variable",
"use_column".  The behavior can also be specified per-function by inserting
one of
        #variable_conflict error
        #variable_conflict use_variable
        #variable_conflict use_column
at the start of the function body.
 
The 8.5 release notes will need to mention using "use_variable" to retain
backward-compatible behavior, although we should encourage people to migrate
to the much less mistake-prone "error" setting.
 
Update the plpgsql documentation to match this and other recent changes.

Continue reading Waiting for 8.5 – PL/pgSQL variable resolution

Getting session variables without touching postgresql.conf

This post has been updated with new code that uses temporary table – the code is at the end of post!

There was this question on Stack Overflow.

For future reference: guy asked how to do session variables – i.e. something he could define once in session, and later reuse in standard sql queries – without modifying postgresql.conf – so usage of custom_variable_classes is forbidden 🙂

While I don't actually see why somebody would want to avoid modifying its postgresql.conf (short of “it's shared hosting and I don't have superuser privileges"), I thought that it will be rather simple, and at the same time, rather interesting.

So, let's do it:

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