(C) DynamoDB - Query

The Query operation finds items based on primary key values. You can query any table or secondary index that has a composite primary key (a partition key and a sort key).

For more information, see https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_Query.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 *ReplyDateTimeS;
    const char *PostedByS;
    const char *IdS;
    int ConsumedCapacityCapacityUnits;
    const char *ConsumedCapacityTableName;
    int Count;
    int ScannedCount;
    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.Query" \
    //   -d '{
    //     "TableName": "Reply",
    //     "IndexName": "PostedBy-Index",
    //     "Limit": 3,
    //     "ConsistentRead": true,
    //     "ProjectionExpression": "Id, PostedBy, ReplyDateTime",
    //     "KeyConditionExpression": "Id = :v1 AND PostedBy BETWEEN :v2a AND :v2b",
    //     "ExpressionAttributeValues": {
    //         ":v1": {"S": "Amazon DynamoDB#DynamoDB Thread 1"},
    //         ":v2a": {"S": "User A"},
    //         ":v2b": {"S": "User C"}
    //     },
    //     "ReturnConsumedCapacity": "TOTAL"
    // }'

    // 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": "Reply",
    //   "IndexName": "PostedBy-Index",
    //   "Limit": 3,
    //   "ConsistentRead": true,
    //   "ProjectionExpression": "Id, PostedBy, ReplyDateTime",
    //   "KeyConditionExpression": "Id = :v1 AND PostedBy BETWEEN :v2a AND :v2b",
    //   "ExpressionAttributeValues": {
    //     ":v1": {
    //       "S": "Amazon DynamoDB#DynamoDB Thread 1"
    //     },
    //     ":v2a": {
    //       "S": "User A"
    //     },
    //     ":v2b": {
    //       "S": "User C"
    //     }
    //   },
    //   "ReturnConsumedCapacity": "TOTAL"
    // }

    json = CkJsonObject_Create();
    CkJsonObject_UpdateString(json,"TableName","Reply");
    CkJsonObject_UpdateString(json,"IndexName","PostedBy-Index");
    CkJsonObject_UpdateInt(json,"Limit",3);
    CkJsonObject_UpdateBool(json,"ConsistentRead",TRUE);
    CkJsonObject_UpdateString(json,"ProjectionExpression","Id, PostedBy, ReplyDateTime");
    CkJsonObject_UpdateString(json,"KeyConditionExpression","Id = :v1 AND PostedBy BETWEEN :v2a AND :v2b");
    CkJsonObject_UpdateString(json,"ExpressionAttributeValues.:v1.S","Amazon DynamoDB#DynamoDB Thread 1");
    CkJsonObject_UpdateString(json,"ExpressionAttributeValues.:v2a.S","User A");
    CkJsonObject_UpdateString(json,"ExpressionAttributeValues.:v2b.S","User C");
    CkJsonObject_UpdateString(json,"ReturnConsumedCapacity","TOTAL");

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

    // {
    //   "ConsumedCapacity": {
    //     "CapacityUnits": 1,
    //     "TableName": "Reply"
    //   },
    //   "Count": 2,
    //   "Items": [
    //     {
    //       "ReplyDateTime": {
    //         "S": "2015-02-18T20:27:36.165Z"
    //       },
    //       "PostedBy": {
    //         "S": "User A"
    //       },
    //       "Id": {
    //         "S": "Amazon DynamoDB#DynamoDB Thread 1"
    //       }
    //     },
    //     {
    //       "ReplyDateTime": {
    //         "S": "2015-02-25T20:27:36.165Z"
    //       },
    //       "PostedBy": {
    //         "S": "User B"
    //       },
    //       "Id": {
    //         "S": "Amazon DynamoDB#DynamoDB Thread 1"
    //       }
    //     }
    //   ],
    //   "ScannedCount": 2
    // }

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

    ConsumedCapacityCapacityUnits = CkJsonObject_IntOf(jsonResponse,"ConsumedCapacity.CapacityUnits");
    ConsumedCapacityTableName = CkJsonObject_stringOf(jsonResponse,"ConsumedCapacity.TableName");
    Count = CkJsonObject_IntOf(jsonResponse,"Count");
    ScannedCount = CkJsonObject_IntOf(jsonResponse,"ScannedCount");
    i = 0;
    count_i = CkJsonObject_SizeOfArray(jsonResponse,"Items");
    while (i < count_i) {
        CkJsonObject_putI(jsonResponse,i);
        ReplyDateTimeS = CkJsonObject_stringOf(jsonResponse,"Items[i].ReplyDateTime.S");
        PostedByS = CkJsonObject_stringOf(jsonResponse,"Items[i].PostedBy.S");
        IdS = CkJsonObject_stringOf(jsonResponse,"Items[i].Id.S");
        i = i + 1;
    }



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

    }