1 type Customer = {id:int; firstName:string; lastName:string}
 2 
 3 type ICusomerRepository =
 4     abstract member GetCustomer : int -> Customer
 5     abstract member InsertCustomer: Customer -> int
 6     abstract member DeleteCustomer: int -> unit
 7 
 8 type InMemoryCustomerRepository ()= 
 9     let customers = [
10             {id=1; firstName = "First"; lastName = "Customer"}
11             {id=2; firstName = "Second"; lastName = "Customer"}
12             {id=3; firstName = "Third"; lastName = "Customer"}]
13     let customers' = new List<Customer>(customers)
14 
15     interface ICusomerRepository with
16         member this.GetCustomer(id:int) =
17             customers' |> Seq.find(fun c -> c.id = id)
18         member this.InsertCustomer(customer: Customer) =
19             let nextId = customers'.Count
20             let customer' = {customer with id=nextId}
21             customers'.Add(customer')
22             nextId
23         member this.DeleteCustomer(id: int) =
24             let customer = customers |> Seq.find(fun c -> c.id = id)
25             customers'.Remove(customer) |> ignore
26 
27 type SqlServerCustomerRepository (connectionString:string) =
28     interface ICusomerRepository with
29         member this.GetCustomer(id:int) =
30             use connection = new SqlConnection(connectionString)
31             let commandText = "Select * from customers where id = " + id.ToString()
32             use command = new SqlCommand(commandText, connection)
33             connection.Open()
34             use reader = command.ExecuteReader()
35             reader.Read() |> ignore
36             {id=reader.[0] :?> int; 
37             firstName=reader.[1] :?> string; 
38             lastName =reader.[2] :?> string}
39                         
40         member this.InsertCustomer(customer: Customer) =
41             use connection = new SqlConnection(connectionString)
42             let commandText = new StringBuilder()
43             commandText.Append("Insert customers values") |> ignore
44             commandText.Append(customer.firstName) |> ignore
45             commandText.Append(",") |> ignore
46             commandText.Append(customer.lastName) |> ignore
47             use command = new SqlCommand(commandText.ToString(), connection)
48             connection.Open()
49             command.ExecuteNonQuery()
50 
51         member this.DeleteCustomer(id: int) =
52             use connection = new SqlConnection(connectionString)
53             let commandText = "Delete customers where id = " + id.ToString()
54             use command = new SqlCommand(commandText, connection)
55             connection.Open()
56             command.ExecuteNonQuery() |> ignore
57 

 1 /// <summary>
 2 /// Interface for Customer Repository implementations.
 3 /// </summary>
 4 type ICusomerRepository =
 5     /// <summary>
 6     /// Get a single validated customer.
 7     /// </summary>
 8     ///<param name="param0">The customer Id</param>
 9     ///<returns>A validated Customer.</returns>
10     abstract member GetCustomer : int -> Customer
11     /// <summary>
12     /// Insert a single validated customer.
13     /// </summary>
14     ///<param name="param0">A validated customer.</param>
15     ///<returns>The Id of the customer, generated by the respository.</returns>
16     abstract member InsertCustomer: Customer -> int
17     /// <summary>
18     /// Deletes a single customer from the respository.
19     /// </summary>
20     ///<param name="param0">The customer Id</param>
21     abstract member DeleteCustomer: int -> unit