(Delphi ActiveX) DynamoDB - DescribeTable

Returns information about the table, including the current status of the table, when it was created, the primary key schema, and any indexes on the table.

For more information, see https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_DescribeTable.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;
AttributeName: WideString;
AttributeType: WideString;
KeyType: WideString;
IndexArn: WideString;
IndexName: WideString;
IndexSizeBytes: Integer;
ItemCount: Integer;
ProjectionProjectionType: WideString;
j: Integer;
count_j: Integer;
TableTableArn: WideString;
TableCreationDateTime: WideString;
TableItemCount: Integer;
TableProvisionedThroughputNumberOfDecreasesToday: Integer;
TableProvisionedThroughputReadCapacityUnits: Integer;
TableProvisionedThroughputWriteCapacityUnits: Integer;
TableTableName: WideString;
TableTableSizeBytes: Integer;
TableTableStatus: WideString;
i: Integer;
count_i: Integer;

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.DescribeTable" \
//   -d '{
//     "TableName":"Thread"
// }'

// 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;
// Don't forget to change the region domain (us-west-2.amazonaws.com) to your particular region.
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"
// }

json := TChilkatJsonObject.Create(Self);
json.UpdateString('TableName','Thread');

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

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

// {
//   "Table": {
//     "TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/Thread",
//     "AttributeDefinitions": [
//       {
//         "AttributeName": "ForumName",
//         "AttributeType": "S"
//       },
//       {
//         "AttributeName": "LastPostDateTime",
//         "AttributeType": "S"
//       },
//       {
//         "AttributeName": "Subject",
//         "AttributeType": "S"
//       }
//     ],
//     "CreationDateTime": 1.363729002358E9,
//     "ItemCount": 0,
//     "KeySchema": [
//       {
//         "AttributeName": "ForumName",
//         "KeyType": "HASH"
//       },
//       {
//         "AttributeName": "Subject",
//         "KeyType": "RANGE"
//       }
//     ],
//     "LocalSecondaryIndexes": [
//       {
//         "IndexArn": "arn:aws:dynamodb:us-west-2:123456789012:table/Thread/index/LastPostIndex",
//         "IndexName": "LastPostIndex",
//         "IndexSizeBytes": 0,
//         "ItemCount": 0,
//         "KeySchema": [
//           {
//             "AttributeName": "ForumName",
//             "KeyType": "HASH"
//           },
//           {
//             "AttributeName": "LastPostDateTime",
//             "KeyType": "RANGE"
//           }
//         ],
//         "Projection": {
//           "ProjectionType": "KEYS_ONLY"
//         }
//       }
//     ],
//     "ProvisionedThroughput": {
//       "NumberOfDecreasesToday": 0,
//       "ReadCapacityUnits": 5,
//       "WriteCapacityUnits": 5
//     },
//     "TableName": "Thread",
//     "TableSizeBytes": 0,
//     "TableStatus": "ACTIVE"
//   }
// }

// Sample code for parsing the JSON response...
// Use the following online tool to generate parsing code from sample JSON:
// Generate Parsing Code from JSON

TableTableArn := jsonResponse.StringOf('Table.TableArn');
TableCreationDateTime := jsonResponse.StringOf('Table.CreationDateTime');
TableItemCount := jsonResponse.IntOf('Table.ItemCount');
TableProvisionedThroughputNumberOfDecreasesToday := jsonResponse.IntOf('Table.ProvisionedThroughput.NumberOfDecreasesToday');
TableProvisionedThroughputReadCapacityUnits := jsonResponse.IntOf('Table.ProvisionedThroughput.ReadCapacityUnits');
TableProvisionedThroughputWriteCapacityUnits := jsonResponse.IntOf('Table.ProvisionedThroughput.WriteCapacityUnits');
TableTableName := jsonResponse.StringOf('Table.TableName');
TableTableSizeBytes := jsonResponse.IntOf('Table.TableSizeBytes');
TableTableStatus := jsonResponse.StringOf('Table.TableStatus');
i := 0;
count_i := jsonResponse.SizeOfArray('Table.AttributeDefinitions');
while i < count_i do
  begin
    jsonResponse.I := i;
    AttributeName := jsonResponse.StringOf('Table.AttributeDefinitions[i].AttributeName');
    AttributeType := jsonResponse.StringOf('Table.AttributeDefinitions[i].AttributeType');
    i := i + 1;
  end;

i := 0;
count_i := jsonResponse.SizeOfArray('Table.KeySchema');
while i < count_i do
  begin
    jsonResponse.I := i;
    AttributeName := jsonResponse.StringOf('Table.KeySchema[i].AttributeName');
    KeyType := jsonResponse.StringOf('Table.KeySchema[i].KeyType');
    i := i + 1;
  end;

i := 0;
count_i := jsonResponse.SizeOfArray('Table.LocalSecondaryIndexes');
while i < count_i do
  begin
    jsonResponse.I := i;
    IndexArn := jsonResponse.StringOf('Table.LocalSecondaryIndexes[i].IndexArn');
    IndexName := jsonResponse.StringOf('Table.LocalSecondaryIndexes[i].IndexName');
    IndexSizeBytes := jsonResponse.IntOf('Table.LocalSecondaryIndexes[i].IndexSizeBytes');
    ItemCount := jsonResponse.IntOf('Table.LocalSecondaryIndexes[i].ItemCount');
    ProjectionProjectionType := jsonResponse.StringOf('Table.LocalSecondaryIndexes[i].Projection.ProjectionType');
    j := 0;
    count_j := jsonResponse.SizeOfArray('Table.LocalSecondaryIndexes[i].KeySchema');
    while j < count_j do
      begin
        jsonResponse.J := j;
        AttributeName := jsonResponse.StringOf('Table.LocalSecondaryIndexes[i].KeySchema[j].AttributeName');
        KeyType := jsonResponse.StringOf('Table.LocalSecondaryIndexes[i].KeySchema[j].KeyType');
        j := j + 1;
      end;

    i := i + 1;
  end;
end;