title: Why does DynamoDB require expressionAttributeValue?
body: <p>I'm learning about how to filter results from a scan or query using Amazon's DynamoDB.  I would expect an example filter to look like <code>filter =&gt; name = Bob</code> or some such. However, Amazon requires the use of a expression attribute such as <code>filter =&gt; name = :person</code> and then <code>ExpressionAttributeValues =&gt; { ":person": {"S": "Bob"}}</code></p>
  
  <p>This is confusing and hurts my head, why can't I use the simple <code>name = Bob</code>?</p>
  
  <hr>
  
  <p>Official docs: <a href="http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/QueryAndScan.html#FilteringResults" rel="noreferrer">http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/QueryAndScan.html#FilteringResults</a></p>
  
  <p>Apparently working example near end: <a href="https://github.com/aws/aws-cli/issues/1073" rel="noreferrer">https://github.com/aws/aws-cli/issues/1073</a></p>