Azure Table Storage - TableEntity map column with a different name

6
votes

I am using Azure Table Storage as my data sink for my Semantic Logging Application Block. When I call a log to be written by my custom EventSource, I get columns similar to the ff.:

  • EventId
  • Payload_username
  • Opcode

I can obtain these columns by creating a TableEntity class that matches the column names exactly (except for EventId, for some reason):

public class ReportLogEntity : TableEntity
{
    public string EventId { get; set; }
    public string Payload_username { get; set; }
    public string Opcode { get; set; }
}

However, I would like to store the data in these columns in differently named properties in my TableEntity:

public class ReportLogEntity : TableEntity
{
    public string Id { get; set; } // maps to "EventId"
    public string Username { get; set; } // maps to "Payload_username"
    public string Operation { get; set; } // maps to "Opcode"
}

Is there a mapper/attribute I can make use of to allow myself to have the column name different from the TableEntity property name?

1
azuremappingazure-storageazure-table-storage

1 Answers

8
votes

You can override ReadEntity and WriteEntity methods of interface ITableEntity to customize your own property names.

    public class ReportLogEntity : TableEntity
    {
        public string PartitionKey { get; set; }
        public string RowKey { get; set; }
        public string Id { get; set; } // maps to "EventId"
        public string Username { get; set; } // maps to "Payload_username"
        public string Operation { get; set; } // maps to "Opcode"

        public override void ReadEntity(IDictionary<string, EntityProperty> properties, OperationContext operationContext)
        {
            this.PartitionKey = properties["PartitionKey"].StringValue;
            this.RowKey = properties["RowKey"].StringValue;
            this.Id = properties["EventId"].StringValue;
            this.Username = properties["Payload_username"].StringValue;
            this.Operation = properties["Opcode"].StringValue;
        }

        public override IDictionary<string, EntityProperty> WriteEntity(OperationContext operationContext)
        {
            var properties = new Dictionary<string, EntityProperty>();
            properties.Add("PartitionKey", new EntityProperty(this.PartitionKey));
            properties.Add("RowKey", new EntityProperty(this.RowKey));
            properties.Add("EventId", new EntityProperty(this.Id));
            properties.Add("Payload_username", new EntityProperty(this.Username));
            properties.Add("Opcode", new EntityProperty(this.Operation));
            return properties;
        }
    }