F#, dotnet core and postgreql query

Program.fs

open System
open Npgsql


type Category = {
    id: int;
    name: string
}

let categoriesSQL = "
    select id, name from categories;
"

let getCategories = 
    use db = new NpgsqlConnection("Host=localhost;Username=dev;Password=dev;Database=myapp")
    db.Open()
    use cmd = new NpgsqlCommand(categoriesSQL, db)
    use reader = cmd.ExecuteReader()
    [while reader.Read() do
        yield { id = reader.GetInt32(reader.GetOrdinal("id"))
                name = reader.GetString(reader.GetOrdinal("name")) }]


[<EntryPoint>]
let main argv =
    let cats = getCategories
    for c in cats do 
        printf "%i :: %s\n" c.id c.name

    0 // return an integer exit code