Unicode C

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. Unicode C

#include <C_CkRestW.h>
#include <C_CkAuthAwsW.h>
#include <C_CkJsonObjectW.h>
#include <C_CkStringBuilderW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkRestW rest;
    HCkAuthAwsW authAws;
    BOOL bTls;
    int port;
    BOOL bAutoReconnect;
    HCkJsonObjectW json;
    HCkStringBuilderW sbRequestBody;
    HCkStringBuilderW sbResponseBody;
    int respStatusCode;
    HCkJsonObjectW jsonResponse;
    const wchar_t *strVal;
    const wchar_t *AttributesLastPostedByS;
    const wchar_t *AttributesForumNameS;
    const wchar_t *AttributesLastPostDateTimeS;
    const wchar_t *AttributesSubjectS;
    const wchar_t *AttributesMessageS;
    int i;
    int count_i;

    success = FALSE;

    rest = CkRestW_Create();

    // 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

    authAws = CkAuthAwsW_Create();
    CkAuthAwsW_putAccessKey(authAws,L"AWS_ACCESS_KEY");
    CkAuthAwsW_putSecretKey(authAws,L"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.)
    CkAuthAwsW_putRegion(authAws,L"us-west-2");
    CkAuthAwsW_putServiceName(authAws,L"dynamodb");
    // SetAuthAws causes Chilkat to automatically add the following headers: Authorization, X-Amz-Date
    CkRestW_SetAuthAws(rest,authAws);

    // URL: https://dynamodb.us-west-2.amazonaws.com/
    bTls = TRUE;
    port = 443;
    bAutoReconnect = TRUE;
    success = CkRestW_Connect(rest,L"dynamodb.us-west-2.amazonaws.com",port,bTls,bAutoReconnect);
    if (success != TRUE) {
        wprintf(L"ConnectFailReason: %d\n",CkRestW_getConnectFailReason(rest));
        wprintf(L"%s\n",CkRestW_lastErrorText(rest));
        CkRestW_Dispose(rest);
        CkAuthAwsW_Dispose(authAws);
        return;
    }

    // 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"
    // }

    json = CkJsonObjectW_Create();
    CkJsonObjectW_UpdateString(json,L"TableName",L"Thread");
    CkJsonObjectW_UpdateString(json,L"Key.ForumName.S",L"Amazon DynamoDB");
    CkJsonObjectW_UpdateString(json,L"Key.Subject.S",L"How do I update multiple items?");
    CkJsonObjectW_UpdateString(json,L"ConditionExpression",L"attribute_not_exists(Replies)");
    CkJsonObjectW_UpdateString(json,L"ReturnValues",L"ALL_OLD");

    CkRestW_AddHeader(rest,L"Content-Type",L"application/x-amz-json-1.0");
    CkRestW_AddHeader(rest,L"X-Amz-Target",L"DynamoDB_20120810.DeleteItem");
    CkRestW_AddHeader(rest,L"Accept-Encoding",L"identity");

    sbRequestBody = CkStringBuilderW_Create();
    CkJsonObjectW_EmitSb(json,sbRequestBody);
    sbResponseBody = CkStringBuilderW_Create();
    success = CkRestW_FullRequestSb(rest,L"POST",L"/",sbRequestBody,sbResponseBody);
    if (success != TRUE) {
        wprintf(L"%s\n",CkRestW_lastErrorText(rest));
        CkRestW_Dispose(rest);
        CkAuthAwsW_Dispose(authAws);
        CkJsonObjectW_Dispose(json);
        CkStringBuilderW_Dispose(sbRequestBody);
        CkStringBuilderW_Dispose(sbResponseBody);
        return;
    }

    respStatusCode = CkRestW_getResponseStatusCode(rest);
    wprintf(L"response status code = %d\n",respStatusCode);
    if (respStatusCode >= 400) {
        wprintf(L"Response Status Code = %d\n",respStatusCode);
        wprintf(L"Response Header:\n");
        wprintf(L"%s\n",CkRestW_responseHeader(rest));
        wprintf(L"Response Body:\n");
        wprintf(L"%s\n",CkStringBuilderW_getAsString(sbResponseBody));
        CkRestW_Dispose(rest);
        CkAuthAwsW_Dispose(authAws);
        CkJsonObjectW_Dispose(json);
        CkStringBuilderW_Dispose(sbRequestBody);
        CkStringBuilderW_Dispose(sbResponseBody);
        return;
    }

    jsonResponse = CkJsonObjectW_Create();
    CkJsonObjectW_LoadSb(jsonResponse,sbResponseBody);

    CkJsonObjectW_putEmitCompact(jsonResponse,FALSE);
    wprintf(L"%s\n",CkJsonObjectW_emit(jsonResponse));

    // 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

    AttributesLastPostedByS = CkJsonObjectW_stringOf(jsonResponse,L"Attributes.LastPostedBy.S");
    AttributesForumNameS = CkJsonObjectW_stringOf(jsonResponse,L"Attributes.ForumName.S");
    AttributesLastPostDateTimeS = CkJsonObjectW_stringOf(jsonResponse,L"Attributes.LastPostDateTime.S");
    AttributesSubjectS = CkJsonObjectW_stringOf(jsonResponse,L"Attributes.Subject.S");
    AttributesMessageS = CkJsonObjectW_stringOf(jsonResponse,L"Attributes.Message.S");
    i = 0;
    count_i = CkJsonObjectW_SizeOfArray(jsonResponse,L"Attributes.Tags.SS");
    while (i < count_i) {
        CkJsonObjectW_putI(jsonResponse,i);
        strVal = CkJsonObjectW_stringOf(jsonResponse,L"Attributes.Tags.SS[i]");
        i = i + 1;
    }



    CkRestW_Dispose(rest);
    CkAuthAwsW_Dispose(authAws);
    CkJsonObjectW_Dispose(json);
    CkStringBuilderW_Dispose(sbRequestBody);
    CkStringBuilderW_Dispose(sbResponseBody);
    CkJsonObjectW_Dispose(jsonResponse);

    }