(C) DynamoDB - UpdateItem

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).

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

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#include <C_CkRest.h>
#include <C_CkAuthAws.h>
#include <C_CkJsonObject.h>
#include <C_CkStringBuilder.h>

void ChilkatSample(void)
    {
    HCkRest rest;
    BOOL success;
    HCkAuthAws authAws;
    BOOL bTls;
    int port;
    BOOL bAutoReconnect;
    HCkJsonObject json;
    HCkStringBuilder sbRequestBody;
    HCkStringBuilder sbResponseBody;
    int respStatusCode;
    HCkJsonObject jsonResponse;
    const char *strVal;
    const char *AttributesLastPostedByS;
    const char *AttributesForumNameS;
    const char *AttributesLastPostDateTimeS;
    const char *AttributesSubjectS;
    const char *AttributesViewsN;
    const char *AttributesMessageS;
    int i;
    int count_i;

    rest = CkRest_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.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

    authAws = CkAuthAws_Create();
    CkAuthAws_putAccessKey(authAws,"AWS_ACCESS_KEY");
    CkAuthAws_putSecretKey(authAws,"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.)
    CkAuthAws_putRegion(authAws,"us-west-2");
    CkAuthAws_putServiceName(authAws,"dynamodb");
    // SetAuthAws causes Chilkat to automatically add the following headers: Authorization, X-Amz-Date
    CkRest_SetAuthAws(rest,authAws);

    // URL: https://dynamodb.us-west-2.amazonaws.com/
    bTls = TRUE;
    port = 443;
    bAutoReconnect = TRUE;
    success = CkRest_Connect(rest,"dynamodb.us-west-2.amazonaws.com",port,bTls,bAutoReconnect);
    if (success != TRUE) {
        printf("ConnectFailReason: %d\n",CkRest_getConnectFailReason(rest));
        printf("%s\n",CkRest_lastErrorText(rest));
        CkRest_Dispose(rest);
        CkAuthAws_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": "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"
    // }

    json = CkJsonObject_Create();
    CkJsonObject_UpdateString(json,"TableName","Thread");
    CkJsonObject_UpdateString(json,"Key.ForumName.S","Amazon DynamoDB");
    CkJsonObject_UpdateString(json,"Key.Subject.S","Maximum number of items?");
    CkJsonObject_UpdateString(json,"UpdateExpression","set LastPostedBy = :val1");
    CkJsonObject_UpdateString(json,"ConditionExpression","LastPostedBy = :val2");
    CkJsonObject_UpdateString(json,"ExpressionAttributeValues.:val1.S","alice@example.com");
    CkJsonObject_UpdateString(json,"ExpressionAttributeValues.:val2.S","fred@example.com");
    CkJsonObject_UpdateString(json,"ReturnValues","ALL_NEW");

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

    sbRequestBody = CkStringBuilder_Create();
    CkJsonObject_EmitSb(json,sbRequestBody);
    sbResponseBody = CkStringBuilder_Create();
    success = CkRest_FullRequestSb(rest,"POST","/",sbRequestBody,sbResponseBody);
    if (success != TRUE) {
        printf("%s\n",CkRest_lastErrorText(rest));
        CkRest_Dispose(rest);
        CkAuthAws_Dispose(authAws);
        CkJsonObject_Dispose(json);
        CkStringBuilder_Dispose(sbRequestBody);
        CkStringBuilder_Dispose(sbResponseBody);
        return;
    }

    respStatusCode = CkRest_getResponseStatusCode(rest);
    printf("response status code = %d\n",respStatusCode);
    if (respStatusCode >= 400) {
        printf("Response Status Code = %d\n",respStatusCode);
        printf("Response Header:\n");
        printf("%s\n",CkRest_responseHeader(rest));
        printf("Response Body:\n");
        printf("%s\n",CkStringBuilder_getAsString(sbResponseBody));
        CkRest_Dispose(rest);
        CkAuthAws_Dispose(authAws);
        CkJsonObject_Dispose(json);
        CkStringBuilder_Dispose(sbRequestBody);
        CkStringBuilder_Dispose(sbResponseBody);
        return;
    }

    jsonResponse = CkJsonObject_Create();
    CkJsonObject_LoadSb(jsonResponse,sbResponseBody);

    CkJsonObject_putEmitCompact(jsonResponse,FALSE);
    printf("%s\n",CkJsonObject_emit(jsonResponse));

    // 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

    AttributesLastPostedByS = CkJsonObject_stringOf(jsonResponse,"Attributes.LastPostedBy.S");
    AttributesForumNameS = CkJsonObject_stringOf(jsonResponse,"Attributes.ForumName.S");
    AttributesLastPostDateTimeS = CkJsonObject_stringOf(jsonResponse,"Attributes.LastPostDateTime.S");
    AttributesSubjectS = CkJsonObject_stringOf(jsonResponse,"Attributes.Subject.S");
    AttributesViewsN = CkJsonObject_stringOf(jsonResponse,"Attributes.Views.N");
    AttributesMessageS = CkJsonObject_stringOf(jsonResponse,"Attributes.Message.S");
    i = 0;
    count_i = CkJsonObject_SizeOfArray(jsonResponse,"Attributes.Tags.SS");
    while (i < count_i) {
        CkJsonObject_putI(jsonResponse,i);
        strVal = CkJsonObject_stringOf(jsonResponse,"Attributes.Tags.SS[i]");
        i = i + 1;
    }



    CkRest_Dispose(rest);
    CkAuthAws_Dispose(authAws);
    CkJsonObject_Dispose(json);
    CkStringBuilder_Dispose(sbRequestBody);
    CkStringBuilder_Dispose(sbResponseBody);
    CkJsonObject_Dispose(jsonResponse);

    }