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FsharpInsteadOfLinqpad.fsx
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FsharpInsteadOfLinqpad.fsx
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(*
From the article "Low risk ways to use F# at work"
http://fsharpforfunandprofit.com/posts/low-risk-ways-to-use-fsharp-at-work/
*)
(* ======================================================
Use F# instead of LINQpad
=== Setup ===
1. Install Chocolately from http://chocolatey.org/
2. Install NuGet command line
cinst nuget.commandline
3. Install FSharp.Data.TypeProviders in same directory as script
nuget install FSharp.Data.TypeProviders -o Packages -ExcludeVersion
====================================================== *)
// sets the current directory to be same as the script directory
System.IO.Directory.SetCurrentDirectory (__SOURCE_DIRECTORY__)
// Requires FSharp.Data under script directory
// nuget install FSharp.Data.TypeProviders -o Packages -ExcludeVersion
#r @"Packages\FSharp.Data.TypeProviders\lib\net40\FSharp.Data.TypeProviders.dll"
#r @"System.Data.Linq.dll"
open System
open System.Linq
open System.Data
open Microsoft.FSharp.Data.TypeProviders
open System.Text.RegularExpressions
[<Literal>]
let connectionString = "Data Source=localhost; Initial Catalog=SqlInFsharp; Integrated Security=True;"
type Sql = SqlDataConnection<connectionString>
let db = Sql.GetDataContext()
// find the number of customers with a gmail domain (in LINQ)
query {
for c in db.Customer do
where (c.Email.EndsWith("gmail.com"))
select c
count
}
// optional, turn logging on
// db.DataContext.Log <- Console.Out
// find the number of customers with a gmail domain (in F#)
db.Customer
|> Seq.filter (fun c -> c.Email.EndsWith("gmail.com"))
|> Seq.length
// find the most popular domain for people born in each decade
let getDomain email =
Regex.Match(email,".*@(.*)").Groups.[1].Value
let getDecade (birthdate:Nullable<DateTime>) =
if birthdate.HasValue then
birthdate.Value.Year / 10 * 10 |> Some
else
None
let topDomain list =
list
|> Seq.distinct
|> Seq.head
|> snd
db.Customer
|> Seq.map (fun c -> getDecade c.Birthdate, getDomain c.Email)
|> Seq.groupBy fst
|> Seq.sortBy fst
|> Seq.map (fun (decade, group) -> (decade,topDomain group))
|> Seq.iter (printfn "%A")