How to Use hypen as key name in dynamo db mapper

Question

I am getting Invalid KeyConditionExpression: Syntax error; token: "-", near:foo-bar when the key name has hypen. I have tried using the with expression attribute names and attribute values but still i am getting the same error. How can i solve this issue?

Invalid KeyConditionExpression: Syntax error; token: "-", near: Map<String,String> 
eak = new HashMap<>(); eak.put("#k","foo-bar"); 
Map<String, AttributeValue> eav = new HashMap<>(); 
eav.put(":v", new AttributeValue().withS("val")); 
DynamoDBQueryExpression<J> queryExpression = new DynamoDBQueryExpression<J>()
             .withKeyConditionExpression("#k = :v")
    ​         .withExpressionAttributeNames(eak) 
             .withExpressionAttributeValues(eav) 
             .withScanIndexForward(true);

Answer 1

It seems you cannot have a column containing a hyphen, foo-bar, while using it the KeyConditionExpression.

In your example, the .withKeyConditionExpression("#k = :v")

• is expended to .f("foo-bar = val"),

• which is similar to .f("foo - bar = val") (note the spaces around -).

The - is no longer interpreted as a character in a column name, but as an operand.

For obvious reasons, this will throw an error, because the - is not in an allowed position.