通过 .NET api 调用时，DynamoDB UpdateItem 不工作

Question

I am using DynamoDb to set up a table which can be updated via API calls. After going through DynamoDB documentation, I have written an update item function in .NET as follows:

public static async Task IntAsync(string phone, string s)
    {
        getAsync(phone).Wait();
        AmazonDynamoDBConfig clientConfig = new AmazonDynamoDBConfig();
        clientConfig.RegionEndpoint = RegionEndpoint.APSouth1;
        try
        {
            using (IAmazonDynamoDB ddbClient = new AmazonDynamoDBClient(clientConfig))
            {
                await ddbClient.UpdateItemAsync(new UpdateItemRequest
                {
                    TableName = "TableName",
                    Key = new Dictionary<string, AttributeValue>
                    {
                        {"ID", new AttributeValue{S=phone} },
                    },
                    ExpressionAttributeNames = new Dictionary<string, string>()
                    {
                        {"#P", "Progress" },
                        {"#A", "attempt"+count.ToString() },
                        {"#S", s }
                    },
                    ExpressionAttributeValues = new Dictionary<string, AttributeValue>()
                    {
                        {":s",new AttributeValue {S=DateTime.Now.ToString()}},

                    },
                    UpdateExpression = "SET #P.#A.#S = :s",
                    ConditionExpression = "attribute_not_exists(#P.#A.#S)"
                });
            }
        }
        catch (Exception e)
        {
            Console.WriteLine("Update Error: " + e.Message);
        }
    }

Issue: This function works fine when called via main and the changes are reflected instantaneously, however calling the same function via a.Net core Get api request does not return any result and continues saying sending request on postman.

The Get Request is as follows:

 public async Task<string> GetAsync(string mobile, string s)
 { 
    await Program.IntAsync(string mobile, string s); 
    return "Done";
 }

However removing the function call from the get request results in the request going through and all the other functions are working perfectly. I have several other update requests carried out via get requests, all of them work perfectly.

Here is what postman keeps saying

Answer 1

Welcome to the community BYNARI
Your code looks good, except for not returning any value, I would change it to have an update response as UpdateItemAsync returns a response:) Change this

public static async Task IntAsync(string phone, string s)
{
    //getAsync(phone).Wait();
    AmazonDynamoDBConfig clientConfig = new AmazonDynamoDBConfig();
    clientConfig.RegionEndpoint = RegionEndpoint.APSouth1;
    try
    {
        using (IAmazonDynamoDB ddbClient = new AmazonDynamoDBClient(clientConfig))
        {
            await ddbClient.UpdateItemAsync(new UpdateItemRequest

To

public static async Task IntAsync(string phone, string s)
    {

        //Added this variable
        UpdateItemResponse updateResponse = null;
        getAsync(phone).Wait();
        AmazonDynamoDBConfig clientConfig = new AmazonDynamoDBConfig();
        clientConfig.RegionEndpoint = RegionEndpoint.APSouth1;
        try
        {
            using (IAmazonDynamoDB ddbClient = new AmazonDynamoDBClient(clientConfig))
            {
              //using the variable
                updateResponse = await ddbClient.UpdateItemAsync(new UpdateItemRequest
***

At the end you should return the updateResponse if you would not do any transforming to it

and you'd of course check if not null then return your updateResponse to your "GetAsync" method
Even in your GetAsync method you'd want to return your UpdateItemResponse

so it would look something like:

 public async Task<string> GetAsync(string mobile, string s)
  { 
     var response = await IntAsync(string mobile, string s); 
     //Then you pack/unpack your response to get your attributes and
     //convert them to string if that is what you need
     var valueToReturn = CustomStringMethod(response.Attributes);
     return valueToReturn;
  }

Here is a link to the aws developer guide that might help you as well:) Update a record in DynamoDB