AzureStorageTable

This projects implements an abstraction for Azure Storage Tables to use POCOs because deriving every entity from ITableEntity or TableEntity looks like a step backwards. The current implementation is intended to be an abstraction to store every existing entity into Azure Table Store.

There are two different principals implemented. The first allows to define an external mapping structure between the existing model and the required fields in Azure Table, e.g. Partition and RowKey. The second option is to decorate existing models with attributes to map the properties to partition and rowkey.

Installation

Install-Package CoreHelpers.WindowsAzure.Storage.Table

Manual Entity Mapper

// create a new user model
var user = new UserModel() { FirstName = "Egon", LastName = "Mueller", Contact = "[email protected]" };

using (var storageContext = new StorageContext(storageKey, storageSecret))
{
  // configure the entity mapper
  storageContext.AddEntityMapper(typeof(UserModel), new DynamicTableEntityMapper() { TableName = "UserProfiles", PartitionKeyPropery = "Contact", RowKeyProperty = "Contact" });

  // ensure the table exists
  storageContext.CreateTable<UserModel>();

  // inser the model
  storageContext.MergeOrInsert<UserModel>(user);

  // query all
  var result = storageContext.Query<UserModel>();

  foreach (var r in result)
  {
    Console.WriteLine(r.FirstName);
  }
}

Attribute Based Entity Mapper

Decorate your existing model

[Storable()]
public class UserModel2
{                       
  [PartitionKey]
  [RowKey]
  public string Contact { get; set; }

  public string FirstName { get; set; } 
  public string LastName { get; set; }                		
}

Configure and use the Storage Context

// create a new user model
var user = new UserModel2() { FirstName = "Egon", LastName = "Mueller", Contact = "[email protected]" };            

using (var storageContext = new StorageContext(storageKey, storageSecret))
{
  // ensure we are using the attributes
  storageContext.AddAttributeMapper();

  // ensure the table exists
  storageContext.CreateTable<UserModel2>();

  // inser the model
  storageContext.MergeOrInsert<UserModel2>(user);

  // query all
  var result = storageContext.Query<UserModel2>();

  foreach (var r in result)
  {
      Console.WriteLine(r.FirstName);
  }
}

Virtual Partition and Row-Keys

When implementing storage schemes in Azure Table sometimes the partition or the row key are combinations out for two or more properties. Because of that the Azure Storage Table components supports virtual partition and row key attributes as follows:

[Storable()]
[VirtualPartitionKey("{{Value1}}-{{Value2}}")]
[VirtualRowKey("{{Value2}}-{{Value3}}")]
public class VirtualPartKeyDemoModel
{
  public string Value1 { get; set;  }
  public string Value2 { get; set;  }				
  public string Value3 { get; set;  }
}

Virtual Array Attributes

When storing arrays in Azure Table store there are two options. The first option is to store it as a JSON payload and the second option is to expand the array with his items to separate properties, e.g.

{ DataElements: [1,2,3,4] }

becomes

DE00	DE01	DE02	DE03
1	2	3	4

in Azure Table Store with the following code:

[Storable(Tablename: "VArrayModels")]
public class VArrayModel
{
  [PartitionKey]
  [RowKey]
  public string UUID { get; set; }

  [VirtualList(PropertyFormat: "DE{{index}}", Digits: 2)]
  public List<int> DataElements { get; set; } = new List<int>();
}

Virtual Dictionary Attributes

When storing dictionaries in Azure Table store there are two options. The first option is to store it as a JSON payload and the second option is to expand the dictionary with his items to separate properties in Azure Table Store with the following code:

[Storable(Tablename: "VDictionaryModels")]
public class VDictionaryModel
{
  [PartitionKey]
  [RowKey]
  public string UUID { get; set; }

  [VirtualDictionary(PropertyPrefix: "DE")]
  public Dictionary<string, int> DataElements { get; set; } = new Dictionary<string, int>();
}

Store as JSON Object Attribute

The store as JSON attribute allows to store refenrenced objects as json payload for a specific property

[Storable(Tablename: "JObjectModel")]
public class JObjectModel
{
 [PartitionKey]
 [RowKey]
 public string UUID { get; set; }
 
 [StoreAsJsonObject]
 public Dictionary<string, string> Data { get; set; } = new Dictionary<string, string>();
}

Store Multiple Objects Types in the same Table

If multiple objects share a common base class, it can be used to store them in the same table. The base class must be decorated with the Storable attribute with the TypeField parameter set. It is best practice to NOT include the type field in the model.

    [Storable(TypeField = "Type")]
    public class BaseModel
    {
        [PartitionKey]
        public string P { get; set; } = "Partition01";

        [RowKey]
        public string R { get; set; } = String.Empty;

    }

	public class MultipleModels1 : MultipleModelsBase
	{
        public string Model1Field { get; set; } = String.Empty;

	}

    public class MultipleModels2 : MultipleModelsBase
    {
        public string Model2Field { get; set; } = String.Empty;

    }

When saving and querying it is important to use the base class as the generic type.

	using (var storageContext = new StorageContext(storageKey, storageSecret))
	{
		storageContext.AddAttributeMapper();

		storageContext.CreateTable<BaseModel>();

		storageContext.MergeOrInsert<BaseModel>(new MultipleModels1() { R = "Row01", Model1Field = "Model1Field" });
		storageContext.MergeOrInsert<BaseModel>(new MultipleModels2() { R = "Row02", Model2Field = "Model2Field" });

		var result = storageContext.Query<BaseModel>();

		foreach (var r in result)
		{
			Console.WriteLine(r.GetType().Name);
		}
	}

Contributing to Azure Storage Table

Fork as usual and go crazy!

Contributors Thank you to the following wonderful people for contributing to Azure Storage Table:

• @petero-dk
• @afrischk