Xojo Plugin

DynamoDB - DeleteItem

See more Amazon DynamoDB Examples

Deletes a single item in a table by primary key. You can perform a conditional delete operation that deletes the item if it exists, or if it has an expected attribute value. Xojo Plugin

Dim success As Boolean
success = False

Dim rest As New Chilkat.Rest

// 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.DeleteItem" \
//   -d '{
//     "TableName": "Thread",
//     "Key": {
//         "ForumName": {
//             "S": "Amazon DynamoDB"
//         },
//         "Subject": {
//             "S": "How do I update multiple items?"
//         }
//     },
//     "ConditionExpression": "attribute_not_exists(Replies)",
//     "ReturnValues": "ALL_OLD"
// }'

// 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 Chilkat.AuthAws
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 Boolean
bTls = True
Dim port As Int32
port = 443
Dim bAutoReconnect As Boolean
bAutoReconnect = True
success = rest.Connect("dynamodb.us-west-2.amazonaws.com",port,bTls,bAutoReconnect)
If (success <> True) Then
    System.DebugLog("ConnectFailReason: " + Str(rest.ConnectFailReason))
    System.DebugLog(rest.LastErrorText)
    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?"
//     }
//   },
//   "ConditionExpression": "attribute_not_exists(Replies)",
//   "ReturnValues": "ALL_OLD"
// }

Dim json As New Chilkat.JsonObject
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("ConditionExpression","attribute_not_exists(Replies)")
success = json.UpdateString("ReturnValues","ALL_OLD")

success = rest.AddHeader("Content-Type","application/x-amz-json-1.0")
success = rest.AddHeader("X-Amz-Target","DynamoDB_20120810.DeleteItem")
success = rest.AddHeader("Accept-Encoding","identity")

Dim sbRequestBody As New Chilkat.StringBuilder
success = json.EmitSb(sbRequestBody)
Dim sbResponseBody As New Chilkat.StringBuilder
success = rest.FullRequestSb("POST","/",sbRequestBody,sbResponseBody)
If (success <> True) Then
    System.DebugLog(rest.LastErrorText)
    Return
End If

Dim respStatusCode As Int32
respStatusCode = rest.ResponseStatusCode
System.DebugLog("response status code = " + Str(respStatusCode))
If (respStatusCode >= 400) Then
    System.DebugLog("Response Status Code = " + Str(respStatusCode))
    System.DebugLog("Response Header:")
    System.DebugLog(rest.ResponseHeader)
    System.DebugLog("Response Body:")
    System.DebugLog(sbResponseBody.GetAsString())
    Return
End If

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

jsonResponse.EmitCompact = False
System.DebugLog(jsonResponse.Emit())

// Sample JSON response:
// (Sample code for parsing the JSON response is shown below)

// {
//   "Attributes": {
//     "LastPostedBy": {
//       "S": "fred@example.com"
//     },
//     "ForumName": {
//       "S": "Amazon DynamoDB"
//     },
//     "LastPostDateTime": {
//       "S": "201303201023"
//     },
//     "Tags": {
//       "SS": [
//         "Update",
//         "Multiple Items",
//         "HelpMe"
//       ]
//     },
//     "Subject": {
//       "S": "How do I update multiple items?"
//     },
//     "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 AttributesLastPostedByS As String
AttributesLastPostedByS = jsonResponse.StringOf("Attributes.LastPostedBy.S")
Dim AttributesForumNameS As String
AttributesForumNameS = jsonResponse.StringOf("Attributes.ForumName.S")
Dim AttributesLastPostDateTimeS As String
AttributesLastPostDateTimeS = jsonResponse.StringOf("Attributes.LastPostDateTime.S")
Dim AttributesSubjectS As String
AttributesSubjectS = jsonResponse.StringOf("Attributes.Subject.S")
Dim AttributesMessageS As String
AttributesMessageS = jsonResponse.StringOf("Attributes.Message.S")
Dim i As Int32
i = 0
Dim count_i As Int32
count_i = jsonResponse.SizeOfArray("Attributes.Tags.SS")
While i < count_i
    jsonResponse.I = i
    strVal = jsonResponse.StringOf("Attributes.Tags.SS[i]")
    i = i + 1
Wend