Revert "Add support for clauses with nil values in Repo.get_by(!)/2 (…

…#2125)"

This reverts commit 8e1b378.

integration_test/cases/repo.exs

@@ -601,21 +601,18 @@ defmodule Ecto.Integration.RepoTest do
   test "get_by(!)" do
     post1 = TestRepo.insert!(%Post{title: "1", text: "hai"})
     post2 = TestRepo.insert!(%Post{title: "2", text: "hello"})
-    post3 = TestRepo.insert!(%Post{title: "3", text: nil})
 
     assert post1 == TestRepo.get_by(Post, id: post1.id)
     assert post1 == TestRepo.get_by(Post, text: post1.text)
     assert post1 == TestRepo.get_by(Post, id: post1.id, text: post1.text)
     assert post2 == TestRepo.get_by(Post, id: to_string(post2.id)) # With casting
     assert nil   == TestRepo.get_by(Post, text: "hey")
     assert nil   == TestRepo.get_by(Post, id: post2.id, text: "hey")
-    assert post3 == TestRepo.get_by(Post, text: nil)
 
     assert post1 == TestRepo.get_by!(Post, id: post1.id)
     assert post1 == TestRepo.get_by!(Post, text: post1.text)
     assert post1 == TestRepo.get_by!(Post, id: post1.id, text: post1.text)
     assert post2 == TestRepo.get_by!(Post, id: to_string(post2.id)) # With casting
-    assert post3 == TestRepo.get_by!(Post, text: nil)
 
     assert post1 == TestRepo.get_by!(Post, %{id: post1.id})
 

lib/ecto/repo/queryable.ex

@@ -347,12 +347,7 @@ defmodule Ecto.Repo.Queryable do
   end
 
   defp query_for_get_by(_repo, queryable, clauses) do
-    Enum.reduce(clauses, queryable, fn
-      ({key, nil}, query) ->
-        Query.where(query, [x], is_nil(field(x, ^key)))
-      ({key, value}, query) ->
-        Query.where(query, [x], field(x, ^key) == ^value)
-    end)
+    Query.where(queryable, [], ^Enum.to_list(clauses))
   end
 
   defp query_for_aggregate(queryable, aggregate, field) do

test/ecto/repo_test.exs

@@ -112,7 +112,6 @@ defmodule Ecto.RepoTest do
   test "validates get_by" do
     TestRepo.get_by(MySchema, id: 123)
     TestRepo.get_by(MySchema, %{id: 123})
-    TestRepo.get_by(MySchema, id: nil)
 
     message = ~r"value `:atom` in `where` cannot be cast to type :id in query"
     assert_raise Ecto.Query.CastError, message, fn ->