从 Azure 表存储中检索记录正在抛出 Object 未设置参考

Question

I have very simple code to retrieve all items from Table Storage. Below code is failing with Object Reference not set exception

    public async Task<List<StringInternTableEntity>> GetAllRowsAsync()
    {
        var entities = new List<StringInternTableEntity>();

        try
        {
            TableContinuationToken token = null;
            do
            {
                var queryResult = await this.azureCloudTable.ExecuteQuerySegmentedAsync(new TableQuery<StringInternTableEntity>(), token);
                entities.AddRange(queryResult.Results);
                token = queryResult.ContinuationToken;
            } while (token != null);

        }
        catch (Exception ex)
        {
            return null;
        }

        return entities;
    }

public class StringInternTableEntity : TableEntity
{
    public StringInternTableEntity()
    {
    }

    public StringInternTableEntity(string runStartTimeStamp, string wordKey)
    {
        PartitionKey = runStartTimeStamp;
        RowKey = wordKey;
    }

    public int NumberValue { get; set; }
}

" at Microsoft.Azure.Cosmos.Table.Extensions.TableExtensionExecutor.<>c__DisplayClass24_0 2.<<ExecuteQuerySegmentedInternalAsync>b__0>d.MoveNext()\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at Microsoft.Azure.Cosmos.Table.Extensions.TableExtensionRetryPolicy.<ExecuteUnderRetryPolicy>d__2 1.MoveNext()\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()\r\n at Citadel.Common.Utils.AzureCloudTableHelper.d__9.MoveNext() in C:\Users\kalsa\source\repos\Citadel3\Citadel.Common\Utils\AzureCloudTableHelper.cs:line 166"

Also in my table I have 1 simple entry.

Answer 1

You may try the below code where I have modified the logic for retrieval of data and finally storing it into the list

 public async Task<List<StringInternTableEntity>> GetAllRowsAsync()
        {
             var query = this.azureCloudTable.CreateQuery<StringInternTableEntity>();
                var result = new List<StringInternTableEntity>();
                var token = new TableContinuationToken();
                do
                {
                    var segment = await this.azureCloudTable.ExecuteQuerySegmentedAsync(query, token);
                    token = segment.ContinuationToken;
                    result.AddRange(segment);
                } while (token != null);
                List<StringInternTableEntity> lstClientID = new List<StringInternTableEntity>();
                foreach (StringInternTableEntity codeMapping in result)
                {
                    lstClientID.Add(codeMapping);
                }
                return lstClientID;
        }