Support schema prefixes (mojotech#91)

* Support schema prefixes

* Fix format

* Code review changes

* Remove prefix from comments and key_values migrations

lib/scrivener/paginater/ecto/query.ex

@@ -14,7 +14,9 @@ defimpl Scrivener.Paginater, for: Ecto.Query do
         options: options
       }) do
     total_entries =
-      Keyword.get_lazy(options, :total_entries, fn -> total_entries(query, repo, caller) end)
+      Keyword.get_lazy(options, :total_entries, fn ->
+        total_entries(query, repo, caller, options)
+      end)
 
     total_pages = total_pages(total_entries, page_size)
     allow_overflow_page_number = Keyword.get(options, :allow_overflow_page_number, false)
@@ -35,20 +37,23 @@ defimpl Scrivener.Paginater, for: Ecto.Query do
 
   defp entries(query, repo, page_number, _, page_size, caller, options) do
     offset = Keyword.get_lazy(options, :offset, fn -> page_size * (page_number - 1) end)
+    prefix = options[:prefix]
 
     query
     |> offset(^offset)
     |> limit(^page_size)
-    |> repo.all(caller: caller)
+    |> repo.all(caller: caller, prefix: prefix)
   end
 
-  defp total_entries(query, repo, caller) do
+  defp total_entries(query, repo, caller, options) do
+    prefix = options[:prefix]
+
     total_entries =
       query
       |> exclude(:preload)
       |> exclude(:order_by)
       |> aggregate()
-      |> repo.one(caller: caller)
+      |> repo.one(caller: caller, prefix: prefix)
 
     total_entries || 0
   end

priv/repo/migrations/04_create_schemas.exs

@@ -0,0 +1,17 @@
+defmodule TestRepo.Migrations.CreateSchemas do
+  use Ecto.Migration
+
+  @prefixes ["tenant_1", "tenant_2"]
+
+  def up do
+    for prefix <- @prefixes do
+      execute "CREATE SCHEMA #{prefix}"
+    end
+  end
+
+  def down do
+    for prefix <- @prefixes do
+      execute "DROP SCHEMA #{prefix}"
+    end
+  end
+end

priv/repo/migrations/05_create_users.exs

@@ -0,0 +1,13 @@
+defmodule TestRepo.Migrations.CreateUsers do
+  use Ecto.Migration
+
+  @prefixes ["tenant_1", "tenant_2"]
+
+  def change do
+    for prefix <- @prefixes do
+      create table(:users, prefix: prefix) do
+        add :email, :string
+      end
+    end
+  end
+end

test/scrivener/paginator/ecto/prefix_test.exs

@@ -0,0 +1,36 @@
+defmodule Scrivener.Paginator.Ecto.PrefixTest do
+  use Scrivener.Ecto.TestCase
+
+  alias Scrivener.Ecto.User
+
+  defp create_users(number, prefix) do
+    Enum.map(1..number, fn i ->
+      %User{email: "user_#{i}@#{prefix}.com"}
+      |> Scrivener.Ecto.Repo.insert!(prefix: prefix)
+    end)
+  end
+
+  @schema_tenant_1 "tenant_1"
+  @schema_tenant_2 "tenant_2"
+
+  describe "prefix" do
+    test "can specify prefix" do
+      create_users(6, @schema_tenant_1)
+      create_users(2, @schema_tenant_2)
+
+      page_tenant_1 = Scrivener.Ecto.Repo.paginate(User, options: [prefix: @schema_tenant_1])
+
+      assert page_tenant_1.page_size == 5
+      assert page_tenant_1.page_number == 1
+      assert page_tenant_1.total_entries == 6
+      assert page_tenant_1.total_pages == 2
+
+      page_tenant_2 = Scrivener.Ecto.Repo.paginate(User, options: [prefix: @schema_tenant_2])
+
+      assert page_tenant_2.page_size == 5
+      assert page_tenant_2.page_number == 1
+      assert page_tenant_2.total_entries == 2
+      assert page_tenant_2.total_pages == 1
+    end
+  end
+end

test/support/user.ex

@@ -0,0 +1,7 @@
+defmodule Scrivener.Ecto.User do
+  use Ecto.Schema
+
+  schema "users" do
+    field(:email, :string)
+  end
+end