[BUG][MySQL] Isolation level not respected when used with access mode

[jreppnow]

PR Info

Hi, I discovered this while writing some data migration logic using IsolationLevel::Serializable, yet getting some results which where definitely not serializable (locks not applied). So I checked the sea_orm transaction code and realized that, if you specify an AccessMode together with your IsolationLevel when begin_with_config(), sea_orm does this in two statements. This is HIGHLY problematic as MySQL expects this to be one query (https://dev.mysql.com/doc/refman/8.0/en/set-transaction.html) and reverts the IsolationLevel setting back to the default, which is ConsistentRead.

This pull requests fixes this issue. Considering that this can very easily result in some very bad data issues, I would consider this a very high urgency issue!!

Bug Fixes

• See above. Basically, if you specify an AccessMode, your IsolationLevel setting is ignored (very bad).

Changes

• Perform the setting in one query.

[tyt2y3]

thank you! I think you're right

[github-actions]

🎉 Released In 1.1.3 🎉

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