PureBasic
PureBasic
DynamoDB - UpdateItem
See more Amazon DynamoDB Examples
Edits an existing item's attributes, or adds a new item to the table if it does not already exist. You can put, delete, or add attribute values. You can also perform a conditional update on an existing item (insert a new attribute name-value pair if it doesn't exist, or replace an existing name-value pair if it has certain expected attribute values).Chilkat PureBasic Downloads
IncludeFile "CkStringBuilder.pb"
IncludeFile "CkAuthAws.pb"
IncludeFile "CkJsonObject.pb"
IncludeFile "CkRest.pb"
Procedure ChilkatExample()
success.i = 0
rest.i = CkRest::ckCreate()
If rest.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
; 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.UpdateItem" \
; -d '{
; "TableName": "Thread",
; "Key": {
; "ForumName": {
; "S": "Amazon DynamoDB"
; },
; "Subject": {
; "S": "Maximum number of items?"
; }
; },
; "UpdateExpression": "set LastPostedBy = :val1",
; "ConditionExpression": "LastPostedBy = :val2",
; "ExpressionAttributeValues": {
; ":val1": {"S": "alice@example.com"},
; ":val2": {"S": "fred@example.com"}
; },
; "ReturnValues": "ALL_NEW"
; }'
; Use the following online tool to generate REST code from a CURL command
; Convert a cURL Command to REST Source Code
authAws.i = CkAuthAws::ckCreate()
If authAws.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
CkAuthAws::setCkAccessKey(authAws, "AWS_ACCESS_KEY")
CkAuthAws::setCkSecretKey(authAws, "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.)
CkAuthAws::setCkRegion(authAws, "us-west-2")
CkAuthAws::setCkServiceName(authAws, "dynamodb")
; SetAuthAws causes Chilkat to automatically add the following headers: Authorization, X-Amz-Date
CkRest::ckSetAuthAws(rest,authAws)
; URL: https://dynamodb.us-west-2.amazonaws.com/
bTls.i = 1
port.i = 443
bAutoReconnect.i = 1
success = CkRest::ckConnect(rest,"dynamodb.us-west-2.amazonaws.com",port,bTls,bAutoReconnect)
If success <> 1
Debug "ConnectFailReason: " + Str(CkRest::ckConnectFailReason(rest))
Debug CkRest::ckLastErrorText(rest)
CkRest::ckDispose(rest)
CkAuthAws::ckDispose(authAws)
ProcedureReturn
EndIf
; 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": "Maximum number of items?"
; }
; },
; "UpdateExpression": "set LastPostedBy = :val1",
; "ConditionExpression": "LastPostedBy = :val2",
; "ExpressionAttributeValues": {
; ":val1": {
; "S": "alice@example.com"
; },
; ":val2": {
; "S": "fred@example.com"
; }
; },
; "ReturnValues": "ALL_NEW"
; }
json.i = CkJsonObject::ckCreate()
If json.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
CkJsonObject::ckUpdateString(json,"TableName","Thread")
CkJsonObject::ckUpdateString(json,"Key.ForumName.S","Amazon DynamoDB")
CkJsonObject::ckUpdateString(json,"Key.Subject.S","Maximum number of items?")
CkJsonObject::ckUpdateString(json,"UpdateExpression","set LastPostedBy = :val1")
CkJsonObject::ckUpdateString(json,"ConditionExpression","LastPostedBy = :val2")
CkJsonObject::ckUpdateString(json,"ExpressionAttributeValues.:val1.S","alice@example.com")
CkJsonObject::ckUpdateString(json,"ExpressionAttributeValues.:val2.S","fred@example.com")
CkJsonObject::ckUpdateString(json,"ReturnValues","ALL_NEW")
CkRest::ckAddHeader(rest,"Content-Type","application/x-amz-json-1.0")
CkRest::ckAddHeader(rest,"X-Amz-Target","DynamoDB_20120810.UpdateItem")
CkRest::ckAddHeader(rest,"Accept-Encoding","identity")
sbRequestBody.i = CkStringBuilder::ckCreate()
If sbRequestBody.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
CkJsonObject::ckEmitSb(json,sbRequestBody)
sbResponseBody.i = CkStringBuilder::ckCreate()
If sbResponseBody.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
success = CkRest::ckFullRequestSb(rest,"POST","/",sbRequestBody,sbResponseBody)
If success <> 1
Debug CkRest::ckLastErrorText(rest)
CkRest::ckDispose(rest)
CkAuthAws::ckDispose(authAws)
CkJsonObject::ckDispose(json)
CkStringBuilder::ckDispose(sbRequestBody)
CkStringBuilder::ckDispose(sbResponseBody)
ProcedureReturn
EndIf
respStatusCode.i = CkRest::ckResponseStatusCode(rest)
Debug "response status code = " + Str(respStatusCode)
If respStatusCode >= 400
Debug "Response Status Code = " + Str(respStatusCode)
Debug "Response Header:"
Debug CkRest::ckResponseHeader(rest)
Debug "Response Body:"
Debug CkStringBuilder::ckGetAsString(sbResponseBody)
CkRest::ckDispose(rest)
CkAuthAws::ckDispose(authAws)
CkJsonObject::ckDispose(json)
CkStringBuilder::ckDispose(sbRequestBody)
CkStringBuilder::ckDispose(sbResponseBody)
ProcedureReturn
EndIf
jsonResponse.i = CkJsonObject::ckCreate()
If jsonResponse.i = 0
Debug "Failed to create object."
ProcedureReturn
EndIf
CkJsonObject::ckLoadSb(jsonResponse,sbResponseBody)
CkJsonObject::setCkEmitCompact(jsonResponse, 0)
Debug CkJsonObject::ckEmit(jsonResponse)
; Sample JSON response:
; (Sample code for parsing the JSON response is shown below)
; {
; "Attributes": {
; "LastPostedBy": {
; "S": "alice@example.com"
; },
; "ForumName": {
; "S": "Amazon DynamoDB"
; },
; "LastPostDateTime": {
; "S": "20130320010350"
; },
; "Tags": {
; "SS": [
; "Update",
; "Multiple Items",
; "HelpMe"
; ]
; },
; "Subject": {
; "S": "Maximum number of items?"
; },
; "Views": {
; "N": "5"
; },
; "Message": {
; "S": "I want to put 10 million data items to an Amazon DynamoDB table. Is there an upper limit?"
; }
; }
; }
; Sample code for parsing the JSON response...
; Use the following online tool to generate parsing code from sample JSON:
; Generate Parsing Code from JSON
strVal.s
AttributesLastPostedByS.s = CkJsonObject::ckStringOf(jsonResponse,"Attributes.LastPostedBy.S")
AttributesForumNameS.s = CkJsonObject::ckStringOf(jsonResponse,"Attributes.ForumName.S")
AttributesLastPostDateTimeS.s = CkJsonObject::ckStringOf(jsonResponse,"Attributes.LastPostDateTime.S")
AttributesSubjectS.s = CkJsonObject::ckStringOf(jsonResponse,"Attributes.Subject.S")
AttributesViewsN.s = CkJsonObject::ckStringOf(jsonResponse,"Attributes.Views.N")
AttributesMessageS.s = CkJsonObject::ckStringOf(jsonResponse,"Attributes.Message.S")
i.i = 0
count_i.i = CkJsonObject::ckSizeOfArray(jsonResponse,"Attributes.Tags.SS")
While i < count_i
CkJsonObject::setCkI(jsonResponse, i)
strVal = CkJsonObject::ckStringOf(jsonResponse,"Attributes.Tags.SS[i]")
i = i + 1
Wend
CkRest::ckDispose(rest)
CkAuthAws::ckDispose(authAws)
CkJsonObject::ckDispose(json)
CkStringBuilder::ckDispose(sbRequestBody)
CkStringBuilder::ckDispose(sbResponseBody)
CkJsonObject::ckDispose(jsonResponse)
ProcedureReturn
EndProcedure