Issue #344: Add basic Set support (ADD and DELETE operations)

[andygonzalez2010]

#344

[whimzyLive]

@andygonzalez2010
Please add tests

[whimzyLive]

@andygonzalez2010

From memory the reason this check was here was due to DynamoDB itself didn't support declaring multiple condition on same attribute within a expression..

With your below example... it would have created an incorrect query expression that would fail when executing against DynamoDB.

Not sure if this has changed since the time it was implemented. Would love to see some references proving this is now supported.

[andygonzalez2010]

im currently running this raw :

TransactWriteItems{
  "TransactItems": [
    {
      "Update": {
        "TableName": "test",
        "Key": {
          "PK": {
            "S": "UserId#111"
          },
          "SK": {
            "S": "RUNNING_TASKS"
          }
        },
        "ExpressionAttributeNames": {
          "#runningTaskIds": "runningTaskIds"
        },
        "ExpressionAttributeValues": {
          ":runningTaskIds": {
            "SS": ["12", "34"]
          },
          ":zero": {
            "N": "0"
          }
        },
        "ConditionExpression":
                "attribute_not_exists(#runningTaskIds) OR size(#runningTaskIds) = :zero",
        "UpdateExpression": "ADD #runningTaskIds :runningTaskIds"
      }
    }
  ]
}

[andygonzalez2010]

@whimzyLive anything else needed here? can we rerun the automated checks?