Snowpack

Snowflake driver for Elixir.

Features

• Automatic decoding and encoding of Elixir values to and from Snowflake's ODBC driver formats
• Supports transactions, prepared queries, pooling and more via DBConnection
• Supports Snowflake ODBC Drivers 2.24.7+

TODO

• Support streaming via DBConnection

Usage

Add :snowpack to your dependencies:

def deps() do
  [
    {:snowpack, "~> 0.6.0"}
  ]
end

Make sure you are using the latest version!

opts = [
  connection: [
    role: "DEV",
    warehouse: System.get_env("SNOWFLAKE_WH"),
    uid: System.get_env("SNOWFLAKE_UID"),
    pwd: System.get_env("SNOWFLAKE_PWD")
  ]
]

{:ok, pid} = Snowpack.start_link(opts)
Snowpack.query!(pid, "select current_user()")

Snowpack.query(pid, "SELECT * FROM data")
{:ok,
 %Snowpack.Result{
   columns: ["id", "title"],
   num_rows: 3,
   rows: [[1, "Data 1"], [2, "Data 2"], [3, "Data 3"]]
 }}

It's recommended to start Snowpack under a supervision tree:

defmodule MyApp.Application do
  use Application

  def start(_type, _args) do
    children = [
      {Snowpack, uid: "snowflake-uid", name: :snowpack}
    ]

    opts = [strategy: :one_for_one, name: MyApp.Supervisor]
    Supervisor.start_link(children, opts)
  end
end

and then we can refer to it by its :name:

Snowpack.query!(:snowpack, "SELECT NOW()").rows
[[~N[2018-12-28 13:42:31]]]

Data representation

Snowflake ODBC       Elixir
-----                ------
NULL                 nil
bool                 true | false
int                  42
float                42.0
decimal              42.0 # (1)
date                 ~D[2013-10-12]
time                 ~T[00:37:14]
datetime             ~N[2013-10-12 00:37:14]  # (2)
timestamp            ~U[2013-10-12 00:37:14Z] # (2)
char                 "é"
text                 "snowpack"
binary               <<1, 2, 3>>
bit                  <<1::size(1), 0::size(1)>>
array                [1, 2, 3]
object               %{key: "value"}

Notes:

1. See Decimal

2. Datetime fields are represented as NaiveDateTime, however a UTC DateTime can be used for encoding as well.

Documentation

Documentation is automatically published to hexdocs.pm on release. You may build the documentation locally with

MIX_ENV=docs mix docs

Contributing

Issues and PRs are welcome! See our organization CONTRIBUTING.md for more information about best-practices and passing CI.