Xojo Plugin

DynamoDB - GetItem

See more Amazon DynamoDB Examples

The GetItem operation returns a set of attributes for the item with the given primary key. If there is no matching item, GetItem does not return any data and there will be no Item element in the response. Xojo Plugin

Dim success As Boolean
success = False

Dim rest As New Chilkat.Rest

// Implements the following CURL command:

// curl -X POST https://dynamodb.us-west-2.amazonaws.com/ \
//   -H "Accept-Encoding: identity" \
//   -H "Content-Type: application/x-amz-json-1.0" \
//   -H "Authorization: AWS4-HMAC-SHA256 Credential=<Credential>, SignedHeaders=<Headers>, Signature=<Signature>" \
//   -H "X-Amz-Date: <Date>" \
//   -H "X-Amz-Target: DynamoDB_20120810.GetItem" \
//   -d '{
//     "TableName": "Thread",
//     "Key": {
//         "ForumName": {
//             "S": "Amazon DynamoDB"
//         },
//         "Subject": {
//             "S": "How do I update multiple items?"
//         }
//     },
//     "ProjectionExpression":"LastPostDateTime, Message, Tags",
//     "ConsistentRead": true,
//     "ReturnConsumedCapacity": "TOTAL"
// }'

// Use the following online tool to generate REST code from a CURL command
// Convert a cURL Command to REST Source Code

Dim authAws As New Chilkat.AuthAws
authAws.AccessKey = "AWS_ACCESS_KEY"
authAws.SecretKey = "AWS_SECRET_KEY"
// Don't forget to change the region to your particular region. (Also make the same change in the call to Connect below.)
authAws.Region = "us-west-2"
authAws.ServiceName = "dynamodb"
// SetAuthAws causes Chilkat to automatically add the following headers: Authorization, X-Amz-Date
success = rest.SetAuthAws(authAws)

// URL: https://dynamodb.us-west-2.amazonaws.com/
Dim bTls As Boolean
bTls = True
Dim port As Int32
port = 443
Dim bAutoReconnect As Boolean
bAutoReconnect = True
success = rest.Connect("dynamodb.us-west-2.amazonaws.com",port,bTls,bAutoReconnect)
If (success <> True) Then
    System.DebugLog("ConnectFailReason: " + Str(rest.ConnectFailReason))
    System.DebugLog(rest.LastErrorText)
    Return
End If

// Note: The above code does not need to be repeatedly called for each REST request.
// The rest object can be setup once, and then many requests can be sent.  Chilkat will automatically
// reconnect within a FullRequest* method as needed.  It is only the very first connection that is explicitly
// made via the Connect method.

// Use this online tool to generate code from sample JSON:
// Generate Code to Create JSON

// The following JSON is sent in the request body.

// {
//   "TableName": "Thread",
//   "Key": {
//     "ForumName": {
//       "S": "Amazon DynamoDB"
//     },
//     "Subject": {
//       "S": "How do I update multiple items?"
//     }
//   },
//   "ProjectionExpression": "LastPostDateTime, Message, Tags",
//   "ConsistentRead": true,
//   "ReturnConsumedCapacity": "TOTAL"
// }

Dim json As New Chilkat.JsonObject
success = json.UpdateString("TableName","Thread")
success = json.UpdateString("Key.ForumName.S","Amazon DynamoDB")
success = json.UpdateString("Key.Subject.S","How do I update multiple items?")
success = json.UpdateString("ProjectionExpression","LastPostDateTime, Message, Tags")
success = json.UpdateBool("ConsistentRead",True)
success = json.UpdateString("ReturnConsumedCapacity","TOTAL")

success = rest.AddHeader("Content-Type","application/x-amz-json-1.0")
success = rest.AddHeader("X-Amz-Target","DynamoDB_20120810.GetItem")
success = rest.AddHeader("Accept-Encoding","identity")

Dim sbRequestBody As New Chilkat.StringBuilder
success = json.EmitSb(sbRequestBody)
Dim sbResponseBody As New Chilkat.StringBuilder
success = rest.FullRequestSb("POST","/",sbRequestBody,sbResponseBody)
If (success <> True) Then
    System.DebugLog(rest.LastErrorText)
    Return
End If

Dim respStatusCode As Int32
respStatusCode = rest.ResponseStatusCode
System.DebugLog("response status code = " + Str(respStatusCode))
If (respStatusCode >= 400) Then
    System.DebugLog("Response Status Code = " + Str(respStatusCode))
    System.DebugLog("Response Header:")
    System.DebugLog(rest.ResponseHeader)
    System.DebugLog("Response Body:")
    System.DebugLog(sbResponseBody.GetAsString())
    Return
End If

Dim jsonResponse As New Chilkat.JsonObject
success = jsonResponse.LoadSb(sbResponseBody)

jsonResponse.EmitCompact = False
System.DebugLog(jsonResponse.Emit())

// Sample JSON response:
// (Sample code for parsing the JSON response is shown below)

// {
//   "ConsumedCapacity": {
//     "CapacityUnits": 1,
//     "TableName": "Thread"
//   },
//   "Item": {
//     "Tags": {
//       "SS": [
//         "Update",
//         "Multiple Items",
//         "HelpMe"
//       ]
//     },
//     "LastPostDateTime": {
//       "S": "201303190436"
//     },
//     "Message": {
//       "S": "I want to update multiple items in a single call. What's the best way to do that?"
//     }
//   }
// }

// Sample code for parsing the JSON response...
// Use the following online tool to generate parsing code from sample JSON:
// Generate Parsing Code from JSON

Dim strVal As String

Dim ConsumedCapacityCapacityUnits As Int32
ConsumedCapacityCapacityUnits = jsonResponse.IntOf("ConsumedCapacity.CapacityUnits")
Dim ConsumedCapacityTableName As String
ConsumedCapacityTableName = jsonResponse.StringOf("ConsumedCapacity.TableName")
Dim ItemLastPostDateTimeS As String
ItemLastPostDateTimeS = jsonResponse.StringOf("Item.LastPostDateTime.S")
Dim ItemMessageS As String
ItemMessageS = jsonResponse.StringOf("Item.Message.S")
Dim i As Int32
i = 0
Dim count_i As Int32
count_i = jsonResponse.SizeOfArray("Item.Tags.SS")
While i < count_i
    jsonResponse.I = i
    strVal = jsonResponse.StringOf("Item.Tags.SS[i]")
    i = i + 1
Wend