Deadlock Error

[tooolbox]

Nice package :)

I'm wondering if CanRetry() should return true for error code 1213? The message is Deadlock found when trying to get lock; try restarting transaction.

I can send a PR if this looks favorable.

[tooolbox]

Eh, it's a little interesting, because you may want to retry a deadlock a few milliseconds later, whereas I could see you waiting a second or so for connection issues. So I personally don't need them all bundled together. Or rather, it might be correct to return true for CanRetry() on a code 1213 error, I would just need to use the lower-level API.

[cenkalti]

As @tooolbox pointed out, in https://dev.mysql.com/doc/refman/8.0/en/innodb-deadlocks-handling.html it is advised to re-issue a transaction if it fails due to deadlock. I think error code 1213 should be added to CanRetry().