Using Postgres with F#

Question

I'm trying to connect F# with an existing Postgresql database in a way that lets me take advantage of the database types during development (via Type Providers or Entity Framework, or a combination thereof).

The raw connection is straightforward to do using Npgsql. For example, the following code segment prints the contents of a Postgres table using F#.

open Npgsql
let connectionString = "(my postgres connection string)"
let getResultSet (connection:NpgsqlConnection) (queryString:string) =
 let command = new NpgsqlCommand(queryString, connection)
 let dataReader = command.ExecuteReader()
 seq {
 while dataReader.Read() do
 yield [for i in [0..dataReader.FieldCount-1] -> dataReader.[i]]
 }
let printResults = 
 let conn = new NpgsqlConnection(connectionString)
 conn.Open()
 try
 let resultSet = getResultSet conn "select * from myTable;"
 for r in resultSet do
 for d in r do
 printf "%s\t" (d.ToString())
 printfn ""
 finally
 conn.Close()

What's the best way to get a Type Provider for this set up or enable using Entity Framework with Postgresql on F#?

Answer 1

Since Npgsql is a ADO.NET provider you should be able to use the SqlEntityConnection type provider with an entity framework DBML file.

For more information see: http://msdn.microsoft.com/en-us/library/hh362322.aspx.