title: how to write aws dynamodb scan filter
body: <p>I have one dynamodb table and one record is like belwo:</p>
  
  <pre><code>{
      "Items": [
          {
              "toObjectId": {
                  "S": "5678"
              },         
              "keyValue": {
                  "S": "7890"
              },
              "aTypeId": {
                  "S": "test"
              },
              "aws:rep:deleting": {
                  "BOOL": false
              },
              "currentAt": {
                  "N": "1582476260000"
              },
              "keyTypeId": {
                  "S": "test2"
              },
              "aId": {
                  "S": "1234"
              },
              "aTypeId_keyTypeId_keyValue_currentAt": {
                  "S": "test_test2_7890_1582476260000"
              },
              "fromObjectId": {
                  "S": "12345"
              },
  
          }
      ],
      "Count": 2562,
      "ScannedCount": 2562,
      "ConsumedCapacity": null
  
  }
  
  </code></pre>
  
  <p>How can I write one aws dynamodb scan/query filter with aws cli to just get aTypeId and aId when aTypeId is "test"?
  And </p>
  
  <pre><code>Primary partition key is aId (String)
  Primary sort key is aTypeId_keyTypeId_keyValue_currentAt (String) 
  </code></pre>
  
  <p>I have tried below but no lucky with it</p>
  
  <pre><code>aws dynamodb query \
      --table-name test \
      --key-condition-expression "aTypeId = :aTypeId" \
      --expression-attribute-values '{
          ":aTypeId": { "S": "test" }     
      }' 
  </code></pre>