Providing connection string to Linq-To-Sql data provider

问题

Is there a way to provide a connection string to Linq-To-Sql data provider in F# from App.Config file.

I have tried the following just for testing:

let mutable connString = @"Data Source=PCSQLEXPRESS;Initial Catalog=NortwindDB;Integrated Security=True"
type SqlConnection = SqlDataConnection<ConnectionString = connString>

but I get an error message "This is not a constant expression or valid custom attribute value"

Thanks

回答1:

The type provider itself requires a hard-coded connection string for generating the type (in your case SqlConnection) to develop against at compile time, but, you can configure the actual connection string used at runtime like so:

type SqlConnection = SqlDataConnection<"Data Source=PCSQLEXPRESS;Initial Catalog=NortwindDB;Integrated Security=True">
let runtimeConnStr = ...
type dataContext = SqlConnection.GetDataContext(runtimeConnStr)

回答2:

Maybe using the "?ConnectionStringName" parameter will get you where you want.

http://msdn.microsoft.com/en-us/library/hh362320(v=VS.110).aspx

回答3:

You might also want to look at the following question which has a solution for this in answers F# Type Providers and Continuous Integration

来源：https://stackoverflow.com/questions/10524710/providing-connection-string-to-linq-to-sql-data-provider