(Excel) DynamoDB - GetItem

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.

For more information, see https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_GetItem.html

Download Excel Class Modules Chilkat Excel Class Modules

Dim rest As Chilkat.Rest
Set rest = Chilkat.NewRest

' 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 Chilkat.AuthAws
Set authAws = Chilkat.NewAuthAws
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
Dim success As Boolean
success = rest.SetAuthAws(authAws)

' URL: https://dynamodb.us-west-2.amazonaws.com/

bTls = True

port = 443

bAutoReconnect = True
success = rest.Connect("dynamodb.us-west-2.amazonaws.com",port,bTls,bAutoReconnect)
If (success <> True) Then
    Debug.Print "ConnectFailReason: "; rest.ConnectFailReason
    Debug.Print rest.LastErrorText
    Exit Sub
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 Chilkat.JsonObject
Set json = Chilkat.NewJsonObject
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 Chilkat.StringBuilder
Set sbRequestBody = Chilkat.NewStringBuilder
success = json.EmitSb(sbRequestBody)
Dim sbResponseBody As Chilkat.StringBuilder
Set sbResponseBody = Chilkat.NewStringBuilder
success = rest.FullRequestSb("POST","/",sbRequestBody,sbResponseBody)
If (success <> True) Then
    Debug.Print rest.LastErrorText
    Exit Sub
End If


respStatusCode = rest.ResponseStatusCode
Debug.Print "response status code = "; respStatusCode
If (respStatusCode >= 400) Then
    Debug.Print "Response Status Code = "; respStatusCode
    Debug.Print "Response Header:"
    Debug.Print rest.ResponseHeader
    Debug.Print "Response Body:"
    Debug.Print sbResponseBody.GetAsString()
    Exit Sub
End If

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

jsonResponse.EmitCompact = False
Debug.Print 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


ConsumedCapacityCapacityUnits = jsonResponse.IntOf("ConsumedCapacity.CapacityUnits")

ConsumedCapacityTableName = jsonResponse.StringOf("ConsumedCapacity.TableName")

ItemLastPostDateTimeS = jsonResponse.StringOf("Item.LastPostDateTime.S")

ItemMessageS = jsonResponse.StringOf("Item.Message.S")

i = 0

count_i = jsonResponse.SizeOfArray("Item.Tags.SS")
Do While i < count_i
    jsonResponse.I = i
    strVal = jsonResponse.StringOf("Item.Tags.SS[i]")
    i = i + 1
Loop