(Perl) 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

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

$rest = chilkat::CkRest->new();

# 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 = chilkat::CkAuthAws->new();
$authAws->put_AccessKey("AWS_ACCESS_KEY");
$authAws->put_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->put_Region("us-west-2");
$authAws->put_ServiceName("dynamodb");
# SetAuthAws causes Chilkat to automatically add the following headers: Authorization, X-Amz-Date
$rest->SetAuthAws($authAws);

# 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) {
    print "ConnectFailReason: " . $rest->get_ConnectFailReason() . "\r\n";
    print $rest->lastErrorText() . "\r\n";
    exit;
}

# 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 = chilkat::CkJsonObject->new();
$json->UpdateString("TableName","Reply");
$json->UpdateString("IndexName","PostedBy-Index");
$json->UpdateInt("Limit",3);
$json->UpdateBool("ConsistentRead",1);
$json->UpdateString("ProjectionExpression","Id, PostedBy, ReplyDateTime");
$json->UpdateString("KeyConditionExpression","Id = :v1 AND PostedBy BETWEEN :v2a AND :v2b");
$json->UpdateString("ExpressionAttributeValues.:v1.S","Amazon DynamoDB#DynamoDB Thread 1");
$json->UpdateString("ExpressionAttributeValues.:v2a.S","User A");
$json->UpdateString("ExpressionAttributeValues.:v2b.S","User C");
$json->UpdateString("ReturnConsumedCapacity","TOTAL");

$rest->AddHeader("Content-Type","application/x-amz-json-1.0");
$rest->AddHeader("X-Amz-Target","DynamoDB_20120810.Query");
$rest->AddHeader("Accept-Encoding","identity");

$sbRequestBody = chilkat::CkStringBuilder->new();
$json->EmitSb($sbRequestBody);
$sbResponseBody = chilkat::CkStringBuilder->new();
$success = $rest->FullRequestSb("POST","/",$sbRequestBody,$sbResponseBody);
if ($success != 1) {
    print $rest->lastErrorText() . "\r\n";
    exit;
}

$respStatusCode = $rest->get_ResponseStatusCode();
print "response status code = " . $respStatusCode . "\r\n";
if ($respStatusCode >= 400) {
    print "Response Status Code = " . $respStatusCode . "\r\n";
    print "Response Header:" . "\r\n";
    print $rest->responseHeader() . "\r\n";
    print "Response Body:" . "\r\n";
    print $sbResponseBody->getAsString() . "\r\n";
    exit;
}

$jsonResponse = chilkat::CkJsonObject->new();
$jsonResponse->LoadSb($sbResponseBody);

$jsonResponse->put_EmitCompact(0);
print $jsonResponse->emit() . "\r\n";

# 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 = $jsonResponse->IntOf("ConsumedCapacity.CapacityUnits");
$ConsumedCapacityTableName = $jsonResponse->stringOf("ConsumedCapacity.TableName");
$Count = $jsonResponse->IntOf("Count");
$ScannedCount = $jsonResponse->IntOf("ScannedCount");
$i = 0;
$count_i = $jsonResponse->SizeOfArray("Items");
while ($i < $count_i) {
    $jsonResponse->put_I($i);
    $ReplyDateTimeS = $jsonResponse->stringOf("Items[i].ReplyDateTime.S");
    $PostedByS = $jsonResponse->stringOf("Items[i].PostedBy.S");
    $IdS = $jsonResponse->stringOf("Items[i].Id.S");
    $i = $i + 1;
}