Get all records from azure table storage

Question

Using this code block

try
{
    StorageCredentials creds = new StorageCredentials(accountName, accountKey);
    CloudStorageAccount account = new CloudStorageAccount(creds, useHttps: true);

    CloudTableClient client = account.CreateCloudTableClient();
    CloudTable table = client.GetTableReference("serviceAlerts");

    TableOperation retrieveOperation = TableOperation.Retrieve<ServiceAlertsEntity>("ServiceAlerts", "b9ccd839-dd99-4358-b90f-46781b87f933");

    TableResult query = table.Execute(retrieveOperation);

    if (query.Result != null)
    {
        outline = outline + ((ServiceAlertsEntity) query.Result).alertMessage + " * ";
    }
    else
    {
        Console.WriteLine("No Alerts");
    }
}
catch (Exception ex)
{
    Console.WriteLine(ex);
}

I am able to retrieve the single record with the partition and rowkey mentioned in the retrieve.

Is there a way I can get all the records that are stored in the partition of ServiceAlerts?

I have tried a wildcard (*) for the second parameter

TableOperation retrieveOperation = TableOperation.Retrieve<ServiceAlertsEntity>(
      "ServiceAlerts","b9ccd839-dd99-4358-b90f-46781b87f933");

but it does not return anything.

Answer 1

You need to specify a TableQuery, this will give you all entities or you can specify a TableQuery.GenerateFilterCondition to filter the rows.

TableQuery<ServiceAlertsEntity> query = new TableQuery<ServiceAlertsEntity>();

foreach (ServiceAlertsEntity entity in table.ExecuteQuery(query))
{
    Console.WriteLine("{0}, {1}\t{2}\t{3}", entity.PartitionKey, entity.RowKey,
                        entity.Field1, entity.Field2);
}

Answer 2

If you need further control over the records being returned, you can use ExecuteQuerySegmentedAsync to retrieve data a page (around 1,000 records) at a time.

    var alerts = new List<ServiceAlertsEntity>();

    var query = new TableQuery<ServiceAlertsEntity>();
    TableContinuationToken continuationToken = null;
    do
    {
        var page = await table.ExecuteQuerySegmentedAsync(query, continuationToken);
        continuationToken = page.ContinuationToken;
        alerts.AddRange(page.Results);
    }
    while (continuationToken != null);

Or if you need to restrict your results, e.g. by Partition Key, you can add a filter condition by adding a Where clause to the query in the above code.

    var pk = "abc";
    var filterPk = TableQuery.GenerateFilterCondition(
        nameof(ServiceAlertsEntity.PartitionKey),
        QueryComparisons.Equal, pk);

    var query = new TableQuery<ServiceAlertsEntity>().Where(filterPk);

MS Azure reference

Answer 3

You're using wrong class. Use TableQuery to retrieve multiple results. https://msdn.microsoft.com/en-us/library/azure/microsoft.windowsazure.storage.table.tablequery.aspx