Automated conversion to a record

I’ve just found the library and it looks pretty decent. However, I found it annoying to be forced to write a method that converts an SqlTable to a record that represents my data.

So that, instead of writting:

let getAllUsers() : User list =
    defaultConnection
    |> Sql.connect
    |> Sql.query "SELECT * FROM \"users\""
    |> Sql.executeTable // SqlTable
    |> Sql.mapEachRow (function
        | [ "user_id", Int id
            "first_name", String fname
            "last_name", String lname ] ->
          let user =
            { UserId = id;
              FirstName = fname;
              LastName = lname }
          Some user
        | _ -> None)

You can write:

let getAllUsers() : User list =
    defaultConnection
    |> Sql.connect
    |> Sql.query "SELECT * FROM \"users\""
    |> Sql.executeTable // SqlTable
    |> Sql.mapEachRow<User>

The solution is pretty basic now and it’s missing some error handling, but I find it a decent starting point.

[<AutoOpen>]
module SqlExts =
    type Sql with
        static member toObj = function
            | Short s -> box s
            | Int i -> box i
            | Long l -> box l
            | String s -> box s
            | Date dt -> box dt
            | Bool b -> box b
            | Number d -> box d
            | Decimal d -> box d
            | Bytea b -> box b
            | HStore hs -> box hs
            | Uuid g -> box g
            | Null -> null
            | Other o -> o

        static member mapRow<'a> (row : SqlRow) = 
            if FSharpType.IsRecord typeof<'a>
                then
                    let args =
                        FSharpType.GetRecordFields typeof<'a>
                        |> Array.map (fun pi -> row |> List.find (fun (name, _) -> pi.Name = name) |> snd |> Sql.toObj)
                    Some <| (FSharpValue.MakeRecord(typeof<'a>, args) :?> 'a)
                else None

[<CompilationRepresentation (CompilationRepresentationFlags.ModuleSuffix)>]
module Sql =
    let mapEachRow<'a> =
        Sql.mapEachRow Sql.mapRow<'a>

I’m going to work in order to improve it. Are you open to pull requests ? 😃

[Zaid-Ajaj]

I am the one who should be thanking you, you did all the awesome work! Goodnight 😄

[bratfizyk]

Yay ! I feel so smart now 😉. Thanks - now I can go to bed with a smile 😉.