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: 100Usage
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.