Wrap DB operations in transactions

[gzcharleszhang]

There are some TODOs in the code where we haven't wrapped some db operations in transactions, which we should.

[mcpenguin]

I believe most of the SQL commands that need to be wrapped in transactions are in the games (blackjack and RPS).

[gzcharleszhang]

the most important ones are coin operations, iirc our update/adjust operations write to both the ledger and balance, we should make sure we wrap both operations in a transaction

[victorzheng02]

Looked into it, doesn't seem like there is a way currently. I have tried but its opening multiple db connections even when I pass in the same db connection to the separate function that updates ledger. Unassigning myself for now.
TryGhost/node-sqlite3#304

[houd1ni]

I believe most of the SQL commands that need to be wrapped in transactions are in the games (blackjack and RPS).

Surprisingly, there's huge performance boost when doing many inserts or other operations with sqlite one after another using transactions. For example, now I have to upload quite large sql dump (and users somehow will) into it via node, and there are suddenly appeared a bunch of problems 😫