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https://github.com/jazzyb/sqlite_ecto

SQLite3 adapter for Ecto
https://github.com/jazzyb/sqlite_ecto

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SQLite3 adapter for Ecto

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README 

        
Sqlite.Ecto [![Build Status](https://travis-ci.org/jazzyb/sqlite_ecto.svg?branch=master "Build Status")](https://travis-ci.org/jazzyb/sqlite_ecto)

==========



`Sqlite.Ecto` is a SQLite3 Adapter for Ecto.



Read [the tutorial](https://github.com/jazzyb/sqlite_ecto/wiki/Basic-Sqlite.Ecto-Tutorial)

for a detailed example of how to setup and use a SQLite repo with Ecto, or

just check-out the CliffsNotes in the sections below if you want to get

started quickly.



## Dependencies



`Sqlite.Ecto` relies on [Sqlitex](https://github.com/mmmries/sqlitex) and

[esqlite](https://github.com/mmzeeman/esqlite).  Since esqlite uses

Erlang NIFs, you will need a valid C compiler to build the library.



## Example



Here is an example usage:



```elixir

# In your config/config.exs file

config :my_app, Repo,

  adapter: Sqlite.Ecto,

  database: "ecto_simple.sqlite3"



# In your application code

defmodule Repo do

  use Ecto.Repo,

    otp_app: :my_app,

    adapter: Sqlite.Ecto

end



defmodule Weather do

  use Ecto.Model



  schema "weather" do

    field :city     # Defaults to type :string

    field :temp_lo, :integer

    field :temp_hi, :integer

    field :prcp,    :float, default: 0.0

  end

end



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

    Repo.all(query)

  end

end

```



## Usage



Add `Sqlite.Ecto` as a dependency in your `mix.exs` file.



```elixir

def deps do

  [{:sqlite_ecto, "~> 1.0.0"}]

end

```



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

```elixir

def application do

  [applications: [:logger, :sqlite_ecto, :ecto]]

end

```



To use the adapter in your repo:

```elixir

defmodule MyApp.Repo do

  use Ecto.Repo,

    otp_app: :my_app,

    adapter: Sqlite.Ecto

end

```



## Unsupported Ecto Constraints



The changeset functions

[`foreign_key_constraint/3`](http://hexdocs.pm/ecto/Ecto.Changeset.html#foreign_key_constraint/3)

and

[`unique_constraint/3`](http://hexdocs.pm/ecto/Ecto.Changeset.html#unique_constraint/3)

are not supported by `Sqlite.Ecto` because the underlying SQLite database does

not provide enough information when such constraints are violated to support

the features.



Note that SQLite **does** support both unique and foreign key constraints via

[`unique_index/3`](http://hexdocs.pm/ecto/Ecto.Migration.html#unique_index/3)

and [`references/2`](http://hexdocs.pm/ecto/Ecto.Migration.html#references/2),

respectively.  When such constraints are violated, they will raise

`Sqlite.Ecto.Error` exceptions.



## Silently Ignored Options



There are a few Ecto options which `Sqlite.Ecto` silently ignores because

SQLite does not support them and raising an error on them does not make sense:

* Most column options will ignore `size`, `precision`, and `scale` constraints

  on types because columns in SQLite have no types, and SQLite will not coerce

  any stored value.  Thus, all "strings" are `TEXT` and "numerics" will have

  arbitrary precision regardless of the declared column constraints.  The lone

  exception to this rule are Decimal types which accept `precision` and

  `scale` options because these constraints are handled in the driver

  software, not the SQLite database.

* If we are altering a table to add a `DATETIME` column with a `NOT NULL`

  constraint, SQLite will require a default value to be provided.  The only

  default value which would make sense in this situation is

  `CURRENT_TIMESTAMP`; however, when adding a column to a table, defaults must

  be constant values.  Therefore, in this situation the `NOT NULL` constraint

  will be ignored so that a default value does not need to be provided.

* When creating an index, `concurrently` and `using` values are silently

  ignored since they do not apply to SQLite.