(Delphi ActiveX) DynamoDB - PutItem

Creates a new item, or replaces an old item with a new item. If an item that has the same primary key as the new item already exists in the specified table, the new item completely replaces the existing item.

For more information, see https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_PutItem.html

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
rest: TChilkatRest;
success: Integer;
authAws: TChilkatAuthAws;
bTls: Integer;
port: Integer;
bAutoReconnect: Integer;
json: TChilkatJsonObject;
sbRequestBody: TChilkatStringBuilder;
sbResponseBody: TChilkatStringBuilder;
respStatusCode: Integer;
jsonResponse: TChilkatJsonObject;

begin
rest := TChilkatRest.Create(Self);

// 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.PutItem" \
//   -d '{
//     "TableName": "Thread",
//     "Item": {
//         "LastPostDateTime": {
//             "S": "201303190422"
//         },
//         "Tags": {
//             "SS": ["Update","Multiple Items","HelpMe"]
//         },
//         "ForumName": {
//             "S": "Amazon DynamoDB"
//         },
//         "Message": {
//             "S": "I want to update multiple items in a single call. What is the best way to do that?"
//         },
//         "Subject": {
//             "S": "How do I update multiple items?"
//         },
//         "LastPostedBy": {
//             "S": "fred@example.com"
//         }
//     },
//     "ConditionExpression": "ForumName <> :f and Subject <> :s",
//     "ExpressionAttributeValues": {
//         ":f": {"S": "Amazon DynamoDB"},
//         ":s": {"S": "How do I update multiple items?"}
//     }
// }'

// Use the following online tool to generate REST code from a CURL command
// Convert a cURL Command to REST Source Code

authAws := TChilkatAuthAws.Create(Self);
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
rest.SetAuthAws(authAws.ControlInterface);

// URL: https://dynamodb.us-west-2.amazonaws.com/
bTls := 1;
port := 443;
bAutoReconnect := 1;
success := rest.Connect('dynamodb.us-west-2.amazonaws.com',port,bTls,bAutoReconnect);
if (success <> 1) then
  begin
    Memo1.Lines.Add('ConnectFailReason: ' + IntToStr(rest.ConnectFailReason));
    Memo1.Lines.Add(rest.LastErrorText);
    Exit;
  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",
//   "Item": {
//     "LastPostDateTime": {
//       "S": "201303190422"
//     },
//     "Tags": {
//       "SS": [
//         "Update",
//         "Multiple Items",
//         "HelpMe"
//       ]
//     },
//     "ForumName": {
//       "S": "Amazon DynamoDB"
//     },
//     "Message": {
//       "S": "I want to update multiple items in a single call. What is the best way to do that?"
//     },
//     "Subject": {
//       "S": "How do I update multiple items?"
//     },
//     "LastPostedBy": {
//       "S": "fred@example.com"
//     }
//   },
//   "ConditionExpression": "ForumName <> :f and Subject <> :s",
//   "ExpressionAttributeValues": {
//     ":f": {
//       "S": "Amazon DynamoDB"
//     },
//     ":s": {
//       "S": "How do I update multiple items?"
//     }
//   }
// }

json := TChilkatJsonObject.Create(Self);
json.UpdateString('TableName','Thread');
json.UpdateString('Item.LastPostDateTime.S','201303190422');
json.UpdateString('Item.Tags.SS[0]','Update');
json.UpdateString('Item.Tags.SS[1]','Multiple Items');
json.UpdateString('Item.Tags.SS[2]','HelpMe');
json.UpdateString('Item.ForumName.S','Amazon DynamoDB');
json.UpdateString('Item.Message.S','I want to update multiple items in a single call. What is the best way to do that?');
json.UpdateString('Item.Subject.S','How do I update multiple items?');
json.UpdateString('Item.LastPostedBy.S','fred@example.com');
json.UpdateString('ConditionExpression','ForumName <> :f and Subject <> :s');
json.UpdateString('ExpressionAttributeValues.:f.S','Amazon DynamoDB');
json.UpdateString('ExpressionAttributeValues.:s.S','How do I update multiple items?');

rest.AddHeader('Content-Type','application/x-amz-json-1.0');
rest.AddHeader('X-Amz-Target','DynamoDB_20120810.PutItem');
rest.AddHeader('Accept-Encoding','identity');

sbRequestBody := TChilkatStringBuilder.Create(Self);
json.EmitSb(sbRequestBody.ControlInterface);
sbResponseBody := TChilkatStringBuilder.Create(Self);
success := rest.FullRequestSb('POST','/',sbRequestBody.ControlInterface,sbResponseBody.ControlInterface);
if (success <> 1) then
  begin
    Memo1.Lines.Add(rest.LastErrorText);
    Exit;
  end;
respStatusCode := rest.ResponseStatusCode;
Memo1.Lines.Add('response status code = ' + IntToStr(respStatusCode));
if (respStatusCode >= 400) then
  begin
    Memo1.Lines.Add('Response Status Code = ' + IntToStr(respStatusCode));
    Memo1.Lines.Add('Response Header:');
    Memo1.Lines.Add(rest.ResponseHeader);
    Memo1.Lines.Add('Response Body:');
    Memo1.Lines.Add(sbResponseBody.GetAsString());
    Exit;
  end;

jsonResponse := TChilkatJsonObject.Create(Self);
jsonResponse.LoadSb(sbResponseBody.ControlInterface);

jsonResponse.EmitCompact := 0;
Memo1.Lines.Add(jsonResponse.Emit());
end;