FatEcto

Description

FAT provides methods for dynamically building queries depending on the parameters it receive.

Currently it's supporting following query functions:

• where
• select
• joins
• order_by
• include
• group_by

Installation

you can get latest from github or published version from hex

{:fat_ecto, github: "tanweerdev/fat_ecto"}
or
{:fat_ecto, "~> 0.1"}

Please do not pass custom $join type for associations which are related via has_many or many_to_many eg

# Please dont pass join like below to avoid un-expected/duplicated records
"$include": %{"doctors" => %{"$join" => "left"}}
# correct way
"$include": %{"doctors" => %{}}

Config

config :my_app, :fat_ecto,
  repo: ExApi.Repo,
  default_limit: 10,
  max_limit: 100

Usage

Once installed you can use FatEcto.FatQuery inside your module and use the build method. Which is the entry method for building every query. And also the main method for the FatEcto.FatQuery.

build(schema_name, params)

Example

defmodule MyApp.Query do
  use FatEcto.FatQuery, otp_app: :my_app, max_limit: 103, default_limit: 34
end

import MyApp.Query
query_opts = %{
      "$select" => %{
        "$fields" => ["name", "location", "rating"],
        "fat_rooms" => ["beds", "capacity"]
      },
      "$order" => %{"id" => "$desc"},
      "$where" => %{"rating" => 4},
      "$group" => ["total_staff", "rating"],
      "$include" => %{
        "fat_doctors" => %{
          "$include" => ["fat_patients"],
          "$where" => %{"name" => "ham"},
          "$order" => %{"id" => "$desc"},
          "$join" => "$right"
        }
      },
      "$right_join" => %{
        "fat_rooms" => %{
          "$on_field" => "id",
          "$on_table_field" => "hospital_id",
          "$select" => ["beds", "capacity", "level"],
          "$where" => %{"incharge" => "John"},
          "$order" => %{"level" => "$asc"}
        }
      }
    }
iex> build(FatEcto.FatHospital, query_opts)
iex> #Ecto.Query<from f0 in FatEcto.FatHospital, right_join: f1 in "fat_rooms",
     on: f0.id == f1.hospital_id, right_join: f2 in assoc(f0, :fat_doctors),
     where: f0.rating == ^4 and ^true, where: f1.incharge == ^"John" and ^true,
     group_by: [f0.total_staff], group_by: [f0.rating], order_by: [asc: f1.level],
     order_by: [desc: f0.id],
     select: merge(map(f0, [:name, :location, :rating, :id, {:fat_rooms, [:beds, :capacity]}]),
     %{^:fat_rooms => map(f1, [:beds, :capacity, :level])}),
     preload: [fat_doctors: #Ecto.Query<from f0 in FatEcto.FatDoctor,
     left_join: f1 in assoc(f0, :fat_patients),
     where: f0.name == ^"ham" and ^true, order_by: [desc: f0.id],
     limit: ^10, offset: ^0, preload: [:fat_patients]>]>

Options:

These are the options supported

Option	Description
$include	Include the assoication model doctors
$include: :fat_patients	Include the assoication patients. Which has association with doctors
$select	Select the fields from hospital and rooms
$where	Added the where attribute in the query
$group	Added the group_by attribute in the query as a list
$order	Sort the result based on the order attribute
$right_join	Specify the type of join
$on_field	Specify the field for join
$on_table_field	Specify the field for join in the joining table

see Docs for more details.