Error
Error Code:
3978
MySQL Error 3978: Invalid FK in Atomic CREATE TABLE
Description
This error occurs when attempting to define a foreign key constraint in specific DDL contexts, such as within a `CREATE TABLE ... AS SELECT` statement or a `CREATE TABLE` operation wrapped in an explicit `START TRANSACTION` block. MySQL disallows foreign key definitions in these scenarios due to limitations in its DDL transactionality.
Error Message
Foreign key creation is not allowed with CREATE TABLE as SELECT and CREATE TABLE with START TRANSACTION statement.
Known Causes
3 known causesFK in CREATE TABLE AS SELECT
Attempting to define a foreign key directly within a `CREATE TABLE ... AS SELECT` statement.
FK in Transactional DDL
Creating a table with a foreign key constraint inside an explicit `START TRANSACTION` block.
Unsupported DDL Combination
Combining foreign key definitions with specific atomic or data-driven table creation methods.
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