Error
Error Code:
54
MongoDB Error 54: Expected Single Value Field
Description
This error indicates that an operation or index expected a field to contain a single scalar value (e.g., string, number, boolean) but encountered an array or an object instead. It commonly occurs during data insertion, updates, or when defining indexes where field atomicity is required.
Error Message
Not Single Value Field
Known Causes
3 known causesUnique Index Violation
Attempting to create or insert data into a unique index where the indexed field contains an array or an object, rather than a single scalar value.
Aggregation Pipeline Mismatch
Using an aggregation operator that expects a single scalar input for a field but receives an array or an object from the previous stage.
Update Operation Type Mismatch
An update operation tries to assign an array or object to a field that is constrained or expected to hold a single scalar value.
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