(PowerBuilder) 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

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

integer li_rc
oleobject loo_Rest
integer li_Success
oleobject loo_AuthAws
integer li_BTls
integer li_Port
integer li_BAutoReconnect
oleobject loo_Json
oleobject loo_SbRequestBody
oleobject loo_SbResponseBody
integer li_RespStatusCode
oleobject loo_JsonResponse
string ls_StrVal
integer li_ConsumedCapacityCapacityUnits
string ls_ConsumedCapacityTableName
string ls_ItemLastPostDateTimeS
string ls_ItemMessageS
integer i
integer li_Count_i

loo_Rest = create oleobject
// Use "Chilkat_9_5_0.Rest" for versions of Chilkat < 10.0.0
li_rc = loo_Rest.ConnectToNewObject("Chilkat.Rest")
if li_rc < 0 then
    destroy loo_Rest
    MessageBox("Error","Connecting to COM object failed")
    return
end if

// 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

loo_AuthAws = create oleobject
// Use "Chilkat_9_5_0.AuthAws" for versions of Chilkat < 10.0.0
li_rc = loo_AuthAws.ConnectToNewObject("Chilkat.AuthAws")

loo_AuthAws.AccessKey = "AWS_ACCESS_KEY"
loo_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.)
loo_AuthAws.Region = "us-west-2"
loo_AuthAws.ServiceName = "dynamodb"
// SetAuthAws causes Chilkat to automatically add the following headers: Authorization, X-Amz-Date
loo_Rest.SetAuthAws(loo_AuthAws)

// URL: https://dynamodb.us-west-2.amazonaws.com/
li_BTls = 1
li_Port = 443
li_BAutoReconnect = 1
li_Success = loo_Rest.Connect("dynamodb.us-west-2.amazonaws.com",li_Port,li_BTls,li_BAutoReconnect)
if li_Success <> 1 then
    Write-Debug "ConnectFailReason: " + string(loo_Rest.ConnectFailReason)
    Write-Debug loo_Rest.LastErrorText
    destroy loo_Rest
    destroy loo_AuthAws
    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"
// }

loo_Json = create oleobject
// Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
li_rc = loo_Json.ConnectToNewObject("Chilkat.JsonObject")

loo_Json.UpdateString("TableName","Thread")
loo_Json.UpdateString("Key.ForumName.S","Amazon DynamoDB")
loo_Json.UpdateString("Key.Subject.S","How do I update multiple items?")
loo_Json.UpdateString("ProjectionExpression","LastPostDateTime, Message, Tags")
loo_Json.UpdateBool("ConsistentRead",1)
loo_Json.UpdateString("ReturnConsumedCapacity","TOTAL")

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

loo_SbRequestBody = create oleobject
// Use "Chilkat_9_5_0.StringBuilder" for versions of Chilkat < 10.0.0
li_rc = loo_SbRequestBody.ConnectToNewObject("Chilkat.StringBuilder")

loo_Json.EmitSb(loo_SbRequestBody)
loo_SbResponseBody = create oleobject
// Use "Chilkat_9_5_0.StringBuilder" for versions of Chilkat < 10.0.0
li_rc = loo_SbResponseBody.ConnectToNewObject("Chilkat.StringBuilder")

li_Success = loo_Rest.FullRequestSb("POST","/",loo_SbRequestBody,loo_SbResponseBody)
if li_Success <> 1 then
    Write-Debug loo_Rest.LastErrorText
    destroy loo_Rest
    destroy loo_AuthAws
    destroy loo_Json
    destroy loo_SbRequestBody
    destroy loo_SbResponseBody
    return
end if

li_RespStatusCode = loo_Rest.ResponseStatusCode
Write-Debug "response status code = " + string(li_RespStatusCode)
if li_RespStatusCode >= 400 then
    Write-Debug "Response Status Code = " + string(li_RespStatusCode)
    Write-Debug "Response Header:"
    Write-Debug loo_Rest.ResponseHeader
    Write-Debug "Response Body:"
    Write-Debug loo_SbResponseBody.GetAsString()
    destroy loo_Rest
    destroy loo_AuthAws
    destroy loo_Json
    destroy loo_SbRequestBody
    destroy loo_SbResponseBody
    return
end if

loo_JsonResponse = create oleobject
// Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
li_rc = loo_JsonResponse.ConnectToNewObject("Chilkat.JsonObject")

loo_JsonResponse.LoadSb(loo_SbResponseBody)

loo_JsonResponse.EmitCompact = 0
Write-Debug loo_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

li_ConsumedCapacityCapacityUnits = loo_JsonResponse.IntOf("ConsumedCapacity.CapacityUnits")
ls_ConsumedCapacityTableName = loo_JsonResponse.StringOf("ConsumedCapacity.TableName")
ls_ItemLastPostDateTimeS = loo_JsonResponse.StringOf("Item.LastPostDateTime.S")
ls_ItemMessageS = loo_JsonResponse.StringOf("Item.Message.S")
i = 0
li_Count_i = loo_JsonResponse.SizeOfArray("Item.Tags.SS")
do while i < li_Count_i
    loo_JsonResponse.I = i
    ls_StrVal = loo_JsonResponse.StringOf("Item.Tags.SS[i]")
    i = i + 1
loop


destroy loo_Rest
destroy loo_AuthAws
destroy loo_Json
destroy loo_SbRequestBody
destroy loo_SbResponseBody
destroy loo_JsonResponse