EctoFragmentExtras

EctoFragmentExtras is a collection of macros to enhance Ecto's fragment() macro.

It adds the following variants which are all macros compiling into regular ecto fragments:

• named_fragment("coalesce(#{:name}, #{:default})", name: user.name, default: ^default_name)
• inline_fragment("coalesce(#{user.name}, #{^default_name})")

Installation

Add ecto_fragment_extras to your list of dependencies in mix.exs:

def deps do
  [{:ecto_fragment_extras, "~> 0.3.0"}]
end

Usage

Named Params

Instead of using Ectos fragment with ?-based interpolation, named_fragment allows you to use named params in your fragments.

named_fragment is implemented as a macro on top of Ecto's fragment macro.

So named_fragment("coalesce(#{:a}, #{:b}, #{:a})", a: 1, b: 2) will be converted to fragment("coalesce(?, ?, ?)", 1, 2, 1) at compile-time.

defmodule TestQuery do
  import Ecto.Query
  import EctoFragmentExtras

  def test_query do
    query = from u in "users",
            select: named_fragment("coalesce(#{:left}, #{:right})", left: "example", right: "input")

    Repo.all(query)
  end
end

Inline Params

Instead of using Ectos fragment with ?-based interpolation, inline_fragment allows you to use inline params directly in your fragment query string.

inline_fragment is implemented as a macro on top of Ecto's fragment macro and, thus, as safe regarding SQL escaping. Please note that it is only safe as long as the interpolation happens within the macro call.

So inline_fragment("coalesce(#{1}, #{2})") will be converted to fragment("coalesce(?, ?, ?)", 1, 2) at compile-time.

defmodule TestQuery do
  import Ecto.Query
  import EctoFragmentExtras

  def test_query do
    default = "Jane Doe"
    query = from u in "users", select: inline_fragment("coalesce(#{u.name}, #{^default})")

    Repo.all(query)
  end
end

frag - a helper combining both

frag is a shorthand which combines both (inline and named fragments) depending on the number of arguments it is called with. When called with just the query string, it interpolates like inline_fragment/1, when called with an additional keyword list param it works like named_fragment/2.

License

The entire project is under the MIT License. Please read the LICENSE file.

Licensing

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, shall be licensed as above, without any additional terms or conditions.