Set transaction isolation level

It’d be nice to have a way to specify the isolation level on the transaction

Also mentioned by @llambda in #138, it’d be nice to have both a better api for injecting connection specific config default settings (currently it’s possible with an afterCreate hook)

[ayroblu]

Implemented as knex.transaction({isolationLevel: 'repeatable read'}) and similar FYI

[Recodify]

For mysql you can simply do:

 await knex.raw('SET TRANSACTION ISOLATION LEVEL READ COMMITTED;');
        await knex.transaction(async (trx) => {
              ...

This will set the transaction isolation level to READ COMMITTED for the next transaction only. See the section ‘Transaction Characteristic’ on: https://dev.mysql.com/doc/refman/8.0/en/set-transaction.html