Re: #Personal#: Reg: Multiple queries in a transaction

From: David G Johnston <david(dot)g(dot)johnston(at)gmail(dot)com>
To: pgsql-general(at)postgresql(dot)org
Subject: Re: #Personal#: Reg: Multiple queries in a transaction
Date: 2015-02-19 08:00:28
Message-ID: 1424332828934-5838540.post@n5.nabble.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

David G Johnston wrote
>
> Medhavi Mahansaria wrote
>> Hi Bill,
>>
>> Thanks!
>>
>> But savepoint concept will not work for me as desired.
>>
>> Is there any other way apart from SAVEPOINT that can be incorporated.
>>
>> I am not using a script. I am writing a c++ program.
>>
>> My problem is that I have 2 cases:
>>
>> Case 1: When Q2 fails (we delete the error), i want to continue to Q3 and
>> commit changes done by Q1 and Q3 once Q3 has executed successfully.
>>
>> Case 2: When Q2 fails, I want it to throw an error. and rollback the
>> changes made by Q1 and not proceed to Q3 at all.
>>
>> Note: This is just a small example. I need a solution for an entire
>> application which follows the same concept across multiple queries.
>>
>> How can I incorporate this?
> Forgo transactions or use savepoints. Those are your tools. If you
> cannot find a way to solve your problem with those tools you either need
> to choose, or build, a different toolbox or explain your actual problem in
> greater detail so that others can see if there are solutions you are
> overlooking.
>
> Or redefine your problem.
>
> David J.

You might be able to write the code in pl/pgsql and just call it from your
application. You have a bit more options for flow control in that compared
to pure SQL.

http://www.postgresql.org/docs/9.3/static/plpgsql-control-structures.html#PLPGSQL-ERROR-TRAPPING

David J.

--
View this message in context: http://postgresql.nabble.com/Personal-Reg-Multiple-queries-in-a-transaction-tp5838427p5838540.html
Sent from the PostgreSQL - general mailing list archive at Nabble.com.

In response to

Browse pgsql-general by date

  From Date Subject
Next Message Daniel LaMotte 2015-02-19 09:46:28 Re: Issue dumping schema using readonly user
Previous Message David G Johnston 2015-02-19 07:56:04 Re: #Personal#: Reg: Multiple queries in a transaction