Error
Error Code:
1766
MySQL Error 1766: Cannot Set Variable During Transaction
Description
This error occurs when you attempt to modify a MySQL system variable while an active transaction is in progress. Such variables often control transactional behavior or session settings that cannot be altered mid-transaction to maintain data integrity and consistency. It typically indicates that a `SET` statement was executed within a `START TRANSACTION ... COMMIT/ROLLBACK` block.
Error Message
The system variable %s cannot be set when there is an ongoing transaction.
Known Causes
3 known causesModifying Transaction-Related Session Variables
Users attempt to change system variables like `autocommit`, `transaction_isolation`, or `sql_mode` that directly impact the properties or behavior of an ongoing transaction.
Incorrect Placement of SET Statements
A `SET` statement targeting a variable that is disallowed during an active transaction is executed between a `START TRANSACTION` and its corresponding `COMMIT` or `ROLLBACK`.
Implicit Transaction Conflicts
A transaction might be implicitly started by certain statements, and a subsequent attempt is made to alter a system variable that cannot be changed while that implicit transaction is active.
Solutions
Coming SoonDetailed step-by-step solutions for this error are being prepared. In the meantime, try these general troubleshooting tips:
General Troubleshooting Tips
- Check the error message carefully for specific details
- Review recent changes that might have caused the error
- Search for the exact error code in the official documentation
- Check log files for additional context
- Try restarting the application or service