using Amazon.DynamoDBv2;

using Amazon.DynamoDBv2.Model;

using Amazon.Runtime;

using Amazon.Util;

using System;

using System.Collections.Generic;

​

using System.Threading.Tasks;

​

namespace QuerySDK

{

    internal class Program

    {

        private static AmazonDynamoDBClient client = new AmazonDynamoDBClient();

​

        // * Converted to return async Task

​

        private static void Main()

        {

            try

            {

                string forumName = "Amazon DynamoDB";

                string threadSubject = "DynamoDB Thread 2";

​

                // call some functions

                // since these are asynchronous tasks, the results we'll get *may* not

                // be in the same order when we called these functions

                var job1 = FindRepliesForAThreadAsync(forumName, threadSubject);

                var job2 = FindRepliesForAThreadSpecifyOptionalLimitAsync(forumName, threadSubject);

                var job3 = FindRepliesForAThreadAsync(forumName, threadSubject);

                var job4 = FindRepliesInLast25DaysWithConfigAsync(forumName, threadSubject);

                var job5 = FindRepliesForAThreadAsync(forumName, threadSubject);

​

                Task.WaitAll(job1, job2, job3, job4, job5); // we await all tasks before we quit Main() console app

            }

            catch (AmazonDynamoDBException ex) { Console.WriteLine(ex.Message); }

            catch (AmazonServiceException ex) { Console.WriteLine(ex.Message); }

            catch (Exception ex) { Console.WriteLine(ex.Message); }

​

            Console.WriteLine("\n>>>>>> All jobs done! End of Program!");

​

        }

​

        private static async Task FindRepliesInLast25DaysWithConfigAsync(string forumName, string threadSubject)

        // using KeyConditionExpression

        {

            Console.WriteLine("\nExecuting FindRepliesInLast25DaysWithConfigAsync()...");

            string replyId = forumName + "#" + threadSubject;

​

            DateTime twoWeeksAgoDate = DateTime.UtcNow - TimeSpan.FromDays(25);

            string twoWeeksAgoString = twoWeeksAgoDate.ToString(AWSSDKUtils.ISO8601DateFormat);

​

            QueryRequest queryRequest = new QueryRequest

            {

                TableName = "Reply",

                KeyConditionExpression = " Id = :v_replyId AND ReplyDateTime > :v_interval ",

                ExpressionAttributeValues = new Dictionary<string, AttributeValue>

                {

                    { ":v_replyId", new AttributeValue{ S = replyId } },

                    { ":v_interval", new AttributeValue { S = twoWeeksAgoString } }

                },

                ReturnConsumedCapacity = ReturnConsumedCapacity.TOTAL,

                ProjectionExpression = "Id, ReplyDateTime, PostedBy",

                // optional parameter

                ConsistentRead = true

            };

​

            // this is synchronous task

            // var queryResponse = client.Query(queryRequest);

​

            // this is an asynchronous task

            QueryResponse queryResponse = await client.QueryAsync(queryRequest).ConfigureAwait(true);

            //Console.WriteLine("Number of RCUs consumed by FindRepliesInLast15DaysWithConfig() : {0}", queryResponse.ConsumedCapacity.CapacityUnits);

            foreach (Dictionary<string, AttributeValue> item in queryResponse.Items)

            {

                PrintAttributes(item);

            }

            Console.WriteLine("--End of FindRepliesInLast25DaysWithConfigAsync().\n");

​

        } // FindRepliesInLast25DaysWithConfig()

​

        private static async Task FindRepliesForAThreadSpecifyOptionalLimitAsync(string forumName, string threadSubject)

        {

            Console.WriteLine("\nExecuting FindRepliesForAThreadSpecifyOptionalLimitAsync()...");

            string replyId = forumName + "#" + threadSubject;

​

            Dictionary<string, AttributeValue> lastKeyEvaluated = null;

            do

            {

                QueryRequest queryRequest = new QueryRequest

                {

                    TableName = "Reply",

                    KeyConditionExpression = " Id = :v_replyId ",

                    ExpressionAttributeValues = new Dictionary<string, AttributeValue>

                    {

                        { ":v_replyId", new AttributeValue{ S = replyId }}

                    },

                    ReturnConsumedCapacity = ReturnConsumedCapacity.TOTAL,

                    Limit = 10,

                    ExclusiveStartKey = lastKeyEvaluated

                };

                QueryResponse queryResponse = await client.QueryAsync(queryRequest).ConfigureAwait(true);

                //Console.WriteLine("\nNumber of RCU FindRepliesForAThreadSpecifyOptionalLimit() consumed: {0} RCU ", queryResponse.ConsumedCapacity.CapacityUnits);

                foreach (Dictionary<string, AttributeValue> item in queryResponse.Items)

                {

                    PrintAttributes(item);

                };

            } while (lastKeyEvaluated != null && lastKeyEvaluated.Count != 0);

​

            Console.WriteLine("--End of FindRepliesForAThreadSpecifyOptionalLimitAsync().\n");

​

        } // FindRepliesForAThreadSpecifyOptionalLimit()

​

        private static async Task FindRepliesForAThreadAsync(string forumName, string threadSubject)

        {

            Console.WriteLine("\nExecuting FindRepliesForAThreadAsync()...");

            string replyId = forumName + "#" + threadSubject;

​

            QueryRequest queryRequest = new QueryRequest()

            {

                TableName = "Reply",

                ReturnConsumedCapacity = ReturnConsumedCapacity.TOTAL,

                KeyConditionExpression = "Id = :v_replyId",

                ExpressionAttributeValues = new Dictionary<string, AttributeValue>

                {

                    { ":v_replyId", new AttributeValue { S = replyId }}

                }

            };

​

            QueryResponse queryResponse = await client.QueryAsync(queryRequest).ConfigureAwait(true);

            //Console.WriteLine("Number of reads (FindRepliesForAThread(): {0}", queryResponse.ConsumedCapacity.CapacityUnits);

            foreach (Dictionary<string, AttributeValue> item in queryResponse.Items)

            {

                PrintAttributes(item);

            }

            Console.WriteLine("--End of FindRepliesForAThreadAsync().\n");

        } // FindRepliesForAThread()

​

        private static void PrintAttributes(Dictionary<string, AttributeValue> Items)

        {

            Console.WriteLine("\n");

            foreach (KeyValuePair<string, AttributeValue> item in Items)

            {

                Console.WriteLine("Key=" + item.Key + ", Value=" +

                    (item.Value.S ?? "") +

                    (item.Value.N ?? "") +

                    (item.Value.SS == null ? "" : string.Join(", ", item.Value.SS.ToArray())) +

                    (item.Value.NS == null ? "" : string.Join(", ", item.Value.NS.ToArray()))

                );

            };

        } // PrintAttributes()

    } // .Program

} // namespace QuerySDK

​

//SAMPLE PROGRAM RUN!!!

​

//EXEC

//====

//Executing FindRepliesForAThreadAsync()...

//Executing FindRepliesForAThreadSpecifyOptionalLimitAsync()...

//Executing FindRepliesForAThreadAsync()...

//Executing FindRepliesInLast25DaysWithConfigAsync()...

//Executing FindRepliesForAThreadAsync()...

​

//RUN #1

//------

//--End of FindRepliesForAThreadSpecifyOptionalLimitAsync().

//--End of FindRepliesInLast25DaysWithConfigAsync().

//--End of FindRepliesForAThreadAsync().

//--End of FindRepliesForAThreadAsync().

//--End of FindRepliesForAThreadAsync().

//>>>>>> All jobs done! End of Program!

​

//RUN #2

//------

//--End of FindRepliesForAThreadAsync().

//--End of FindRepliesInLast25DaysWithConfigAsync().

//--End of FindRepliesForAThreadSpecifyOptionalLimitAsync().

//--End of FindRepliesForAThreadAsync().

//--End of FindRepliesForAThreadAsync().

//>>>>>> All jobs done! End of Program!

​

//RUN #3

//------

//--End of FindRepliesForAThreadAsync().

//--End of FindRepliesInLast25DaysWithConfigAsync().

//--End of FindRepliesForAThreadAsync().

//--End of FindRepliesForAThreadSpecifyOptionalLimitAsync().

//--End of FindRepliesForAThreadAsync().

//>>>>>> All jobs done! End of Program!