Error: ValidationException: Invalid KeyConditionExpression: Attribute name is a reserved keyword;

DynamoDB has a list of reserved keywords that you cannot use in your queries or scans directly. If you need to write an expression that contains one of them, you need to use ExpressionAttributeNames to replace reserved word with a placeholder. For example, this query with reserved keyword:

        params = {
            TableName : ‘MY_TABLE’,
            FilterExpression: "timestamp BETWEEN :startDate AND :endDate",
            ExpressionAttributeValues: { 
                ":startDate": ""+startDate, 
                ":endDate": ""+endDate
            } 
        }
        

Replace with:

        params = {
            TableName : ‘MY_TABLE’,
            FilterExpression: "#dynobase_timestamp BETWEEN :startDate AND :endDate",
            ExpressionAttributeValues: { 
                ":startDate": startDate, 
                ":endDate": endDate
            },
            ExpressionAttributeNames: { "#dynobase_timestamp": "timestamp" }
        }