Visual Basic 6.0

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. Visual Basic 6.0

Dim success As Long
success = 0

Dim rest As New ChilkatRest

' 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 ChilkatAuthAws
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 Long
bTls = 1
Dim port As Long
port = 443
Dim bAutoReconnect As Long
bAutoReconnect = 1
success = rest.Connect("dynamodb.us-west-2.amazonaws.com",port,bTls,bAutoReconnect)
If (success <> 1) 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 New ChilkatJsonObject
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",1)
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 ChilkatStringBuilder
success = json.EmitSb(sbRequestBody)
Dim sbResponseBody As New ChilkatStringBuilder
success = rest.FullRequestSb("POST","/",sbRequestBody,sbResponseBody)
If (success <> 1) Then
    Debug.Print rest.LastErrorText
    Exit Sub
End If

Dim respStatusCode As Long
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 New ChilkatJsonObject
success = jsonResponse.LoadSb(sbResponseBody)

jsonResponse.EmitCompact = 0
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

Dim strVal As String

Dim ConsumedCapacityCapacityUnits As Long
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 Long
i = 0
Dim count_i As Long
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