Defql

Create elixir functions with SQL as a body.

Installation

If available in Hex, the package can be installed by adding defql to your list of dependencies in mix.exs:

defp deps do
  [
    {:defql, "~> 0.1.1"},
    {:postgrex, ">= 0.13.0"}, # optional
  ]
end

Configuration

It requires adapter key, and adapter specific options.

Use with ecto:

config :defql, connection: [
  adapter: Defql.Adapter.Ecto.Postgres,
  repo: YourApp.Repo
]

Use standalone connection:

config :defql, connection: [
  adapter: Defql.Adapter.Postgres,
  hostname: "localhost",
  username: "username",
  password: "password",
  database: "my_db",
  pool: DBConnection.Poolboy,
  pool_size: 1
]

Usage

We can define module to have access to our database:

defmodule UserQuery do
  use Defql

  defselect get(conds), table: :users, columns: [:name, :email]
  definsert add(params), table: :users
  defupdate update(params, conds), table: :users
  defdelete delete(conds), table: :users

  defquery get_by_name(name, limit) do
    "SELECT * FROM users WHERE name = $name LIMIT $limit"
  end
end

Right now we have easy access to users in database:

UserQuery.get(id: "3") # => {:ok, [%{...}]}
UserQuery.add(name: "Smbdy") # => {:ok, [%{...}]}
UserQuery.update([name: "Other"],[id: "2"]) # => {:ok, [%{...}]}
UserQuery.delete(id: "2") # => {:ok, [%{...}]}

UserQuery.get_by_name("Ela", 4) # => {:ok, [%{...}, %{...}]}

We can also define common table for the whole module.

defmodule UserQuery do
  use Defql, table: :users

  defselect get(conds), columns: [:name, :email]
  definsert add(params)
  defupdate update(params, conds)
  defdelete delete(conds)
end

%{...} It's a hash with user properties straight from database.

Supported condition statements:

• user_id: [1,2,3,4]
• user_id: {:in, [1,2,3,4,5]}
• name: {:like, "%john%"}
• name: {:ilike, "%john"}

TODO

• MySQL support
• Cleanup ECTO adapter
• Support database errors
• Transactions

Thank you!