HOW TO: Connect to SQL Server Compact from F#

I have previously blogged about connection to SQL Server Compact from other technologies than pure ADO.NET:

ASP Classic

VBA (Excel)

Silverlight

PowerShell

F# version 3.0 in Visual Studio 2012 makes it relatively easy to connect to a SQL Server Compact database (I am NOT a F# programmer, and even I could connect, so it must be very easy!).

In this blog post I will show the required steps to connect to a SQL Server Compact 4.0 database file and start using it via Entity Framework with F#.

In VS 2012 (currently RC), create a new F# application:

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Now add references to the required libraries (Entity Framework and F# Type Providers):

FSharp.Data.TypeProviders
System.Data.Entity
System.Data.Linq

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I order to access SQL Server Compact via EF 4 from F#, and Entity Data Model file (.EDMX) file is required. And the EDMX Wizard and Designer only works with C# and VB.NET projects, so to create this, add a Visual C# Console project to the solution:

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Now add the EDMX file to this project, right click the project, select Add, New Item…, Data,

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Select generate from database, and point to the desired SQL Server Compact 4.0 database.

Just say no:

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The Console project now contains an EDMX file, and a useful connection string in app.config.

Now go back to the F# project clear program.fs, and add the following “using” statements:

open System
open System.Data.Linq
open System.Data.EntityClient
open Microsoft.FSharp.Data.TypeProviders

Grab the connectionString value from the console project app config, and add this line:

let internal connectionString = "metadata=res://*/;provider=System.Data.SqlServerCe.4.0;provider connection string='data source=C:\Data\SQLCE\Test\nw40.sdf';"

Notice the changes to the provider connection string – =" has been change to single quote, and backslashes have been escaped.

Now add the EDMX file from the Console project to the F# project as Content:

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You can now initialize the EF type provider like so:

type internal edmx = EdmxFile<"NWModel.edmx">

And start using the context like this:

let internal context = new edmx.nw40Model.nw40Entities(connectionString)

let internal res = query { for supplier in context.Suppliers do select supplier }

res|> Seq.iter (fun supplier -> printfn "%s" supplier.Company_Name)

let wait = Console.ReadKey()

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