Crane is an simple to use ORM to minimise the job of mapping SQL queries to POCO.

Some key Features:

• Support: SQL Server, task based async pattern, .NET >= 4.5.0 and Core >= 2.0
• Cache queries in memory or a custom provider of your choice.
• Add custom mappings for column aliases so your stored procedures dont have to suffer readability issues.

Getting started

// Basic instantiation 

// Sql Server
private readonly ICraneAccess _sqlAccess = new SqlServerAccess("your connection string");

// Or use your favourite DI framework...

// .NET Core
public void ConfigureServices(IServiceCollection services)
{
    services.AddTransient<ICraneAccess>(x => new SqlServerAccess("your connection string", new MemoryCacheProvider()));
    services.AddMvc();
}

// Autofac
var builder = new ContainerBuilder();
builder.Register<ICraneAccess>(x => new SqlServerAccess("your connection string", new MemoryCacheProvider())).InstancePerDependency();

Container = builder.Build();

Examples

Selects all products defined by 'dbo.GetProducts'.

CREATE PROCEDURE [dbo].[GetProducts]
AS
BEGIN
    SELECT p.Id, p.ProductName, p.SupplierId, 
    p.UnitPrice, p.Package, p.IsDiscontinued 
    FROM dbo.Product p
END

// Returns IEnumerable of type Product.
var products = _sqlAccess.Query().ExecuteReader<Product>("dbo.GetProducts");

---

Easily add parameters. The below example gets all products with a supplier id of 2. You can chain the AddSqlParamater method more than once if you have more than one parameter to include.

CREATE PROCEDURE [dbo].[GetProducts]
	@SupplierId int
AS
BEGIN
    SELECT p.Id, p.ProductName, p.UnitPrice,
    p.Package, p.IsDiscontinued 
    FROM dbo.Product p
    WHERE p.SupplierId = @SupplierId
END

 
var products = _sqlAccess.Query()
    .AddSqlParameter("@SupplierId", 2)
    .ExecuteReader<Product>("dbo.GetProducts");

---

If you're using a column alias in your select statement, add one or many custom column mappings depending on your procedure.

CREATE PROCEDURE [dbo].[GetProducts]
AS
BEGIN
    SELECT p.Id as [Product Id], p.ProductName as [Product Name]
    FROM dbo.Product p
END

    var products = _sqlAccess.Query()
    .CustomColumnMapping<Product>(x => x.Id, "Product Id")
    .CustomColumnMapping<Product>(x => x.ProductName, "Product Name")
    .ExecuteReader<Product>("dbo.GetProducts");

---

Caching

Crane supports caching for tuning application performance.

Currently only MemoryCacheProvider (which uses MemoryCache by .NET) is supported. You can easily implement your own cache provider (e.g. Redis) by extending the AbstractCraneCacheProvider interface. Once a cache provider is registered, you can supply 'cacheKey' as a named parameter to ExecuteReader queries.

dataAccess.Query()
.ExecuteReader<Product>("dbo.GetProducts", cacheKey: "customer_x_products");

If you want to force refresh the cache so a fresh copy is retrieved next call, you can use the RemoveFromCache method.

dataAccess.RemoveFromCache("customer_x_products");

---

Advanced Caching

Apply policies to cache keys globally or with a regular expresssion.

var cacheProvider = new MemoryCacheProvider();

// Note: Default policy if global or custom policies not added is infinite expiration. 

// Global policy applied if nothing specific is found. 
cacheProvider.SetGlobalPolicy(new SprocCachePolicy()
{
    AbsoluteExpiration = TimeSpan.FromDays(1)
});

// Regular expression will have precedence over global or default policy. Add as many policies as you need.  
cacheProvider.AddPolicy(@"user-products-.*", new SprocCachePolicy()
{
    AbsoluteExpiration = TimeSpan.FromMinutes(30)
});

_sqlAccess.RegisterCacheProvider(cacheProvider);

---

Reusing an existing DbConnection

Crane by default will manage the connection for you. If however you're in a TransactionScope and want to reuse an existing DbConnection and not have Crane open and close the connection for you, you can supply the named parameter 'unmanagedConn'.

dataAccess.Query().ExecuteReader<Product>("dbo.GetProducts", unmanagedConn: conn);

Note: 95% of the time you don't need this. Let Crane handle the connection for you for most cases.

---

Table Joins

Join up to eight other related entities. When mapping a join you must supply the partitionOn and callback parameters. Please observe the below procedure carefully and pay special attention to the columns 'ProductName' and 'Id'. These are the two arguments for the partitionOn parameter. partitionOn arguments are separated by a pipe '|'. The callback parameter is a delegate and is invoked for every row that is processed. This is your chance to do any mappings for your TResult reference type. Because Crane reads row by row, some relationships may require an intermediate dictionary.

The below example retrieves a single product with an Id of 62 and its associated supplier. It's a 1:1 relationship.

CREATE PROCEDURE [dbo].[GetProductAndSupplier]
	@Id int
AS
BEGIN
    SET NOCOUNT ON;
    
    SELECT p.ProductName, p.UnitPrice, p.Package, p.IsDiscontinued,
    s.Id, s.CompanyName, s.ContactName, s.ContactTitle, s.City, 
    s.Country, s.Phone, s.Fax 
    FROM dbo.Product p
    INNER JOIN dbo.Supplier s
    ON p.SupplierId = s.Id
    WHERE p.Id = @Id
END

Product product = null;
 
product = _sqlAccess.Query()
    .AddSqlParameter("@Id", 62)
    .ExecuteReader<Product, Supplier>("[dbo].[GetProductAndSupplier]", (p, s) =>
    {
        p.Supplier = s;
    }, partitionOn: "ProductName|Id")
    .FirstOrDefault();


Assert.AreEqual("Tarte au sucre", product?.ProductName);
Assert.AreEqual("Chantal Goulet", product?.Supplier.ContactName);

---

Get customer and their order(s).

CREATE PROCEDURE [dbo].[GetCustomerAndOrders]
	@FirstName nvarchar(40),
	@LastName nvarchar(40)
AS
BEGIN
    SET NOCOUNT ON;

    SELECT c.Id, c.FirstName, c.LastName, c.City, c.Country, c.Phone, 
    o.Id as [OrderId], o.OrderDate, o.OrderNumber, o.TotalAmount
    FROM dbo.Customer c
    LEFT JOIN dbo.[Order] o
    ON o.CustomerId = c.Id
    WHERE c.FirstName = @FirstName
    AND c.LastName = @LastName
END

Customer cust = null;

_sqlAccess.Query()
    .AddSqlParameter("@FirstName", "Thomas")
    .AddSqlParameter("@LastName", "Hardy")
    .CustomColumnMapping<Order>(x => x.Id, "OrderId")
    .ExecuteReader<Customer, Order>("dbo.GetCustomerAndOrders", (c, o) =>
    {
        if (cust == null)
        {
            cust = c;
            cust.CustomerOrders = new List<Order>();
        }
        
        if (o != null)
            cust.CustomerOrders.Add(o);

    }, partitionOn: "Id|OrderId");


Assert.IsNotNull(cust);
Assert.AreEqual(13, cust.CustomerOrders.Count);

---

A slightly more complex example getting all customers and all orders. This demonstrates the use of a dictionary to only get distinct customers.

CREATE PROCEDURE GetAllCustomersAndOrders
AS
BEGIN
    SET NOCOUNT ON;

    SELECT *
    FROM dbo.Customer c
    LEFT JOIN dbo.[Order] o
    ON c.Id = o.CustomerId
END
GO

Dictionary<int, Customer> customerDic = new Dictionary<int, Customer>();


_sqlAccess.Query()
    .ExecuteReader<Customer, Order>("dbo.GetAllCustomersAndOrders", (c, o) =>
    {
    	Customer customer;

        if (!customerDic.TryGetValue(c.Id, out customer))
        {
            customer = c;                            
            customer.CustomerOrders = new List<Order>();
            customerDic.Add(customer.Id, customer);
        }

        if (o != null)
            customer.CustomerOrders.Add(o);

        }, partitionOn: "Id|Id");
    }

    Assert.IsTrue(customerDic.Count > 0);