Error
Error Code:
1855
MySQL Error 1855: FTS_DOC_ID Visibility Conflict
Description
This error occurs when an operation attempts to alter a table such that the internal `FTS_DOC_ID` column, used by MySQL for Full-Text Search, would be replaced or made visible as a user-defined column. MySQL does not permit this as `FTS_DOC_ID` is a system-managed internal column crucial for FTS functionality and cannot be user-controlled.
Error Message
Cannot replace hidden FTS_DOC_ID with a user-visible one
Known Causes
3 known causesAltering FTS Table Structure
Attempting to modify a table that has a Full-Text Search (FTS) index in a way that conflicts with or tries to expose the internal `FTS_DOC_ID` column.
Column Name Collision
Introducing or renaming a user-defined column to `FTS_DOC_ID` in a table that already uses this name internally for Full-Text Search, leading to a system name conflict.
Improper Table Creation or Copy
Creating a new table or copying data from an FTS-enabled table without correctly handling its internal FTS metadata, resulting in an `FTS_DOC_ID` conflict in the new structure.
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