Just create a unique index on EMAIL column and handle error if it comes
Thanks,
Atul Goel
-----Original Message-----
From: pgsql-general-owner@postgresql.org [mailto:pgsql-general-owner@postgresql.org] On Behalf Of Gnanakumar
Sent: 18 January 2012 11:04
To: pgsql-general@postgresql.org
Subject: [GENERAL] On duplicate ignore
Hi,
Ours is a web-based application. We're trying to implement ON DUPLICATE IGNORE for one of our application table, named
EMAILLIST. After a quick Google search, I'm finding the following "easy & convenient" single SQL statement syntax to
followwith:
INSERT INTO EMAILLIST (EMAIL)
SELECT 'john@example.net'
WHERE NOT EXISTS (SELECT 1 FROM EMAILLIST WHERE EMAIL = 'john@example.net');
My question is, in a single threaded INSERT, this will *definitely* work.
Since ours is a web-based application, will this work out in a concurrent multi-threaded environment too? In other
words,will it be truly unique when INSERT calls are concurrent?
Regards,
Gnanam
--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general
The information contained in this email is strictly confidential and for the use of the addressee only, unless
otherwiseindicated. If you are not the intended recipient, please do not read, copy, use or disclose to others this
messageor any attachment. Please also notify the sender by replying to this email or by telephone (+44 (0)20 7896 0011)
andthen delete the email and any copies of it. Opinions, conclusions (etc) that do not relate to the official business
ofthis company shall be understood as neither given nor endorsed by it. IG Group Holdings plc is a company registered
inEngland and Wales under number 04677092. VAT registration number 761 2978 07. Registered Office: Cannon Bridge House,
25Dowgate Hill, London EC4R 2YA. Listed on the London Stock Exchange. Its subsidiaries IG Markets Limited and IG Index
Limitedare authorised and regulated by the Financial Services Authority (IG Markets Limited FSA registration number
195355and IG Index Limited FSA registration number 114059).