Error: DynamoDB ConditionalCheckFailedException

Answered by Rafal Wilinski
Solution
In DynamoDB, when writing operations, Condition Expressions can be specified to determine whether operation should be actually performed.
ConditionalCheckFailedException is an error thrown by AWS SDK or CLI when the ConditionExpression evaluates to false. This is especially useful if you want to atomically check data without fetching and then writing. Examples include:
- Create an item if such doesn't exist yet
- Delete an item only if some attribute is defined
- Update user attribute only if user is active
Either remove ConditionExpression from your DynamoDB code or change parameters and data so the condition can be satisfied.
Other Common DynamoDB Errors (with Solutions)
- DynamoDB cannot do operations on a non-existent table
- DynamoDB Local Docker Not Working
- DynamoDB Mapper Could Not Instantiate Class
- DynamoDB Delete Not Working
- name key is not defined dynamodb
- dynamodb cannot convert undefined to object
- dynamodb query key condition not supported
- DynamoDB Key element does not match the schema
- AWS Lambda DynamoDB Stream Error
- ImportError: No module named boto3 (DynamoDB)
- ExpressionAttributeValues contains invalid value: One or more parameter values were invalid: An AttributeValue may not contain an empty string
- dynamodb converter not found for enhancedtype
- DynamoDB No Provisioned Throughput specified for the table
- Float types are not supported. Use decimal types instead.
- 'dynamodb' object has no attribute 'table'
Spend less time in the AWS console, use Dynobase.
Start your 7-day free trial today
Product Features
DynamoDB Tools
DynamoDB Info
© 2026 Dynobase