Is mysql insert from subquery atomic?

Question

If I do a query like

insert into sometable b + 10 from select b from (select b from sometable order by id desc limit 1)

Is this operation atomic? That is, would it be possible for an insert into sometable to change the value of b AFTER is has been queried, but before the insert completes, causing the insert to get the wrong value?

Sometimes - see https://dev.mysql.com/doc/refman/5.6/en/set-transaction.html — symcbean, Nov 25 '15 at 12:41

score -1 · Answer 1 · answered Nov 25 '15 at 12:33

-1

My guess is that it is not. You can lock it to make sure it doesn't change:

INSERT INTO sometable (b)
SELECT b+10
FROM sometable
ORDER BY id DESC
LIMIT 1
LOCK IN SHARE MODE

answered Nov 25 '15 at 12:33

Vatev

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"My guess" is not an answer. Anyone can guess. – Benubird Nov 26 '15 at 09:58

Is mysql insert from subquery atomic?

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