TDS Adapter for Ecto
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Tds.Ecto (Ecto v2)

MSSQL / TDS Adapter for Ecto2

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# In your config/config.exs file add MSSQL connection options
# By default it use port 1433, different port can be specified with
# port: 1434
# option and named instance with
# instance: "instance_name"
config :my_app, Repo,
  database: "ecto_simple",
  username: "mssql",
  password: "mssql",
  hostname: "localhost"

# In your application code
defmodule Repo do
  use Ecto.Repo,
    otp_app: :my_app,
    adapter: Tds.Ecto

defmodule Weather do
  use Ecto.Schema

  schema "weather" do
    field :city     # Defaults to type :string
    field :temp_lo, :integer
    field :temp_hi, :integer
    field :prcp,    :float, default: 0.0

defmodule Simple do
  import Ecto.Query

  def sample_query do
    query = from w in Weather,
          where: w.prcp > 0 or is_nil(w.prcp),
         select: w

Also, if you need to map table to schema other than [dbo], simple use @schema_prefix "your_schema", eg:

defmodule Invoices.Invoice do
  use Ecto.Schema

  @schema_prefix :invoices
  schema "invoices" do
    field :due_date, :datetime
    field :sum, :float


Add Tds as a dependency in your mix.exs file.

def deps do
  [{:tds_ecto, "~> 2.2"}]

You should also update your applications list to include both projects:

def application do
  [applications: [:logger, :tds_ecto, :ecto]]

To use the adapter in your repo:

defmodule MyApp.Repo do
  use Ecto.Repo,
    otp_app: :my_app,
    adapter: Tds.Ecto

tds_ecto relies on pattern matching against error messages to extract constraint names. If your SQL server is not configured to English as its default language you may add an after_connect hook to your repo and set English as the language for Ecto connections.

def after_connect(conn) do
  Tds.Ecto.Connection.query(conn, "SET LANGUAGE English", [], [])

For additional information on usage please see the documentation for Ecto.

Data Type Mapping

MSSQL             	Ecto/Tds.Ecto
----------        	------
nvarchar            :string
varchar             Tds.VarChar
char                :binary
varbinary           :binary
float               :float
decimal             :decimal
integer             :integer
bit                 :boolean
uniqueidentifier    :uuid
datetime            :datetime
date                :date
time                :time


To contribute you need to compile Tds from source and test it:

$ git clone
$ cd tds_ecto
$ mix test

Tests will try to connect to localhost using sa as username with predefined password mssql, but you can set environment variables to override any, like so: SQL_USERNAME=myuser; SQL_PASSWORD=mypassword; SQL_HOSTNAME=sqlserver.local; mix test or if you are using windows then SET SQL_USERNAME=myuser && SET SQL_PASSWORD=mypassword && SET SQL_HOSTNAME=sqlserver.local && mix test. Please note that tests will run againes default sql server instance.

Additionally SQL authentication needs to be used for connecting and testing.If you override default test settings, make sure either that yor user has sysadmin privilegies to add the user test_user with access to the database test_db, or simply add manualy test_user on your server. See one of the test files for the connection information and port number.


Copyright 2014, 2015, 2016, 2017 LiveHelpNow

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.