DataFlex
DataFlex
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 DataFlex Downloads
Use ChilkatAx-win32.pkg
Procedure Test
Boolean iSuccess
Handle hoRest
Variant vAuthAws
Handle hoAuthAws
Boolean iBTls
Integer iPort
Boolean iBAutoReconnect
Handle hoJson
Variant vSbRequestBody
Handle hoSbRequestBody
Variant vSbResponseBody
Handle hoSbResponseBody
Integer iRespStatusCode
Handle hoJsonResponse
String sStrVal
String sAttributesLastPostedByS
String sAttributesForumNameS
String sAttributesLastPostDateTimeS
String sAttributesSubjectS
String sAttributesViewsN
String sAttributesMessageS
Integer i
Integer iCount_i
String sTemp1
Integer iTemp1
Move False To iSuccess
Get Create (RefClass(cComChilkatRest)) To hoRest
If (Not(IsComObjectCreated(hoRest))) Begin
Send CreateComObject of hoRest
End
// 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
Get Create (RefClass(cComChilkatAuthAws)) To hoAuthAws
If (Not(IsComObjectCreated(hoAuthAws))) Begin
Send CreateComObject of hoAuthAws
End
Set ComAccessKey Of hoAuthAws To "AWS_ACCESS_KEY"
Set ComSecretKey Of hoAuthAws To "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.)
Set ComRegion Of hoAuthAws To "us-west-2"
Set ComServiceName Of hoAuthAws To "dynamodb"
// SetAuthAws causes Chilkat to automatically add the following headers: Authorization, X-Amz-Date
Get pvComObject of hoAuthAws to vAuthAws
Get ComSetAuthAws Of hoRest vAuthAws To iSuccess
// URL: https://dynamodb.us-west-2.amazonaws.com/
Move True To iBTls
Move 443 To iPort
Move True To iBAutoReconnect
Get ComConnect Of hoRest "dynamodb.us-west-2.amazonaws.com" iPort iBTls iBAutoReconnect To iSuccess
If (iSuccess <> True) Begin
Get ComConnectFailReason Of hoRest To iTemp1
Showln "ConnectFailReason: " iTemp1
Get ComLastErrorText Of hoRest To sTemp1
Showln sTemp1
Procedure_Return
End
// 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"
// }
Get Create (RefClass(cComChilkatJsonObject)) To hoJson
If (Not(IsComObjectCreated(hoJson))) Begin
Send CreateComObject of hoJson
End
Get ComUpdateString Of hoJson "TableName" "Thread" To iSuccess
Get ComUpdateString Of hoJson "Key.ForumName.S" "Amazon DynamoDB" To iSuccess
Get ComUpdateString Of hoJson "Key.Subject.S" "Maximum number of items?" To iSuccess
Get ComUpdateString Of hoJson "UpdateExpression" "set LastPostedBy = :val1" To iSuccess
Get ComUpdateString Of hoJson "ConditionExpression" "LastPostedBy = :val2" To iSuccess
Get ComUpdateString Of hoJson "ExpressionAttributeValues.:val1.S" "alice@example.com" To iSuccess
Get ComUpdateString Of hoJson "ExpressionAttributeValues.:val2.S" "fred@example.com" To iSuccess
Get ComUpdateString Of hoJson "ReturnValues" "ALL_NEW" To iSuccess
Get ComAddHeader Of hoRest "Content-Type" "application/x-amz-json-1.0" To iSuccess
Get ComAddHeader Of hoRest "X-Amz-Target" "DynamoDB_20120810.UpdateItem" To iSuccess
Get ComAddHeader Of hoRest "Accept-Encoding" "identity" To iSuccess
Get Create (RefClass(cComChilkatStringBuilder)) To hoSbRequestBody
If (Not(IsComObjectCreated(hoSbRequestBody))) Begin
Send CreateComObject of hoSbRequestBody
End
Get pvComObject of hoSbRequestBody to vSbRequestBody
Get ComEmitSb Of hoJson vSbRequestBody To iSuccess
Get Create (RefClass(cComChilkatStringBuilder)) To hoSbResponseBody
If (Not(IsComObjectCreated(hoSbResponseBody))) Begin
Send CreateComObject of hoSbResponseBody
End
Get pvComObject of hoSbRequestBody to vSbRequestBody
Get pvComObject of hoSbResponseBody to vSbResponseBody
Get ComFullRequestSb Of hoRest "POST" "/" vSbRequestBody vSbResponseBody To iSuccess
If (iSuccess <> True) Begin
Get ComLastErrorText Of hoRest To sTemp1
Showln sTemp1
Procedure_Return
End
Get ComResponseStatusCode Of hoRest To iRespStatusCode
Showln "response status code = " iRespStatusCode
If (iRespStatusCode >= 400) Begin
Showln "Response Status Code = " iRespStatusCode
Showln "Response Header:"
Get ComResponseHeader Of hoRest To sTemp1
Showln sTemp1
Showln "Response Body:"
Get ComGetAsString Of hoSbResponseBody To sTemp1
Showln sTemp1
Procedure_Return
End
Get Create (RefClass(cComChilkatJsonObject)) To hoJsonResponse
If (Not(IsComObjectCreated(hoJsonResponse))) Begin
Send CreateComObject of hoJsonResponse
End
Get pvComObject of hoSbResponseBody to vSbResponseBody
Get ComLoadSb Of hoJsonResponse vSbResponseBody To iSuccess
Set ComEmitCompact Of hoJsonResponse To False
Get ComEmit Of hoJsonResponse To sTemp1
Showln sTemp1
// 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
Get ComStringOf Of hoJsonResponse "Attributes.LastPostedBy.S" To sAttributesLastPostedByS
Get ComStringOf Of hoJsonResponse "Attributes.ForumName.S" To sAttributesForumNameS
Get ComStringOf Of hoJsonResponse "Attributes.LastPostDateTime.S" To sAttributesLastPostDateTimeS
Get ComStringOf Of hoJsonResponse "Attributes.Subject.S" To sAttributesSubjectS
Get ComStringOf Of hoJsonResponse "Attributes.Views.N" To sAttributesViewsN
Get ComStringOf Of hoJsonResponse "Attributes.Message.S" To sAttributesMessageS
Move 0 To i
Get ComSizeOfArray Of hoJsonResponse "Attributes.Tags.SS" To iCount_i
While (i < iCount_i)
Set ComI Of hoJsonResponse To i
Get ComStringOf Of hoJsonResponse "Attributes.Tags.SS[i]" To sStrVal
Move (i + 1) To i
Loop
End_Procedure