Comments on: How to write INSERT IF NOT EXISTS queries in standard SQL

By: Brent

Brent — Sat, 15 Mar 2008 23:01:02 +0000

For MySQL users, this idea might work, although it may be clunky. I’d be happy to hear any means of improving efficiency here!

/*1. Check if record exists. Assign @ifExists the recordID.*/
SELECT @ifExists := ifnull(recordID,0) FROM table where url = ‘http://www.disney.com’;

/*2. Assign @stmt to a valid SQL statement. If recordID = 0, the record doesn’t exist, so use an INSERT statement; otherwise, use a dummy statement. Remember to escape apostrophes within the control clause, as in “\’”.*/
SET @stmt = IF(@ifExists = 0,’INSERT INTO target (field1) values(\’field1 value\’);’,'SELECT null;’);

/*3. Prepare and Execute @stmt*/
PREPARE stmt FROM @stmt;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

By: Sonia

Sonia — Wed, 27 Feb 2008 20:03:01 +0000

Thanks so much. This really sped up my query in comparison to ‘not exists’.

By: manovich

manovich — Tue, 15 Jan 2008 23:35:26 +0000

Two approaches to update database row if exists, insert if not - http://dotnettipoftheday.org/tips/update-insert-row-sql.aspx

By: Bruno Tarcha

Bruno Tarcha — Mon, 07 Jan 2008 19:18:32 +0000

Awesome solution!!
This saved me so much time that I cannot even estimate.
Thank you very much and congratulations!

By: Bogdan

Bogdan — Thu, 18 Oct 2007 13:14:00 +0000

to Chris: IGNORE also ignores several other error conditions (such as charset conversion, invalid values etc). Thus it is advisable to first test the query without IGNORE…

It might be a good alternative to use INSERT … ON DUPLICATE KEY UPDATE syntax with doing nothing in the UPDATE part, but I didn’t test this solution myself.

By: arasu

arasu — Sun, 09 Sep 2007 16:04:34 +0000

the information given to me was valuable.. thank for the information..

By: Leo Muniz

Leo Muniz — Thu, 28 Jun 2007 00:37:56 +0000

Hey guys,
I have a doubt. How can I select * except the columns that I specify?
Example:
table users
id_name, description, age

select * except age from users;

i wanna this because i’ll probably need to insert columns at the table and want there are in the select query without having to rewrite it.
thanks

By: Leo Muniz

Leo Muniz — Wed, 27 Jun 2007 22:33:38 +0000

Hey Chris,
I would like just to thank you. I’ve been searching for this solution the hole afternoon and now i have it because of you. Thanks.

By: Universalist (Chris)

Universalist (Chris) — Tue, 22 May 2007 01:37:22 +0000

Alright, with pleasure.

The query is “insert IGNORE into url(url) values(…)”.

Explanation:
Lets assume the scenario mentioned above.
We want to do the following (impossible): “insert if not exists into url(url) values(…)”

Now, `url` is the primary key, thus has to be unique. This makes mySQL throw an error if we try to insert a value that already exists and, more importantly: the new value won’t be inserted.

Thats practically already an “insert if not exists”. We just have to make mySQL not throw an error if it encounters duplicate unique values, and that’s exactly what “ignore” is for (it has only this purpose, to my knowledge).

So we just do “insert IGNORE into url(url) values(…)” and everybody should be happy :D

By: Win

Win — Wed, 09 May 2007 21:32:20 +0000

Hello Chris I am looking for that exact solution for MySQL but I can’t find the query could you post it again “INSERT IF NOT EXISTS”.

Thanks