Support values lists (#4270)

Co-authored-by: narrowtux <narrow.m@gmail.com>

integration_test/cases/repo.exs

@@ -2174,4 +2174,80 @@ defmodule Ecto.Integration.RepoTest do
       assert updated_second.public == false
     end
   end
+
+  describe "values list" do
+    @describetag :values_list
+
+    test "all" do
+      uuid_module = uuid_module(TestRepo.__adapter__())
+      uuid = uuid_module.generate()
+
+      # Without select
+      values = [%{bid: uuid, visits: 1}, %{bid: uuid, visits: 2}]
+      types = %{bid: uuid_module, visits: :integer}
+      query = from v in values(values, types)
+      assert TestRepo.all(query) == values
+
+      # With select
+      query = select(query, [v], {v, v.bid})
+      assert TestRepo.all(query) == Enum.map(values, &{&1, &1.bid})
+    end
+
+    test "all with join" do
+      uuid_module = uuid_module(TestRepo.__adapter__())
+      uuid = uuid_module.generate()
+
+      values1 = [%{bid: uuid, visits: 1}, %{bid: uuid, visits: 2}]
+      values2 = [%{bid: uuid, visits: 1}]
+      types = %{bid: uuid_module, visits: :integer}
+
+      query =
+        from v1 in values(values1, types),
+          join: v2 in values(values2, types),
+          on: v1.visits == v2.visits
+
+      assert TestRepo.all(query) == [%{bid: uuid, visits: 1}]
+    end
+
+    test "delete_all" do
+      uuid_module = uuid_module(TestRepo.__adapter__())
+      uuid = uuid_module.generate()
+
+      _p1 = TestRepo.insert!(%Post{bid: uuid, visits: 1})
+      p2 = TestRepo.insert!(%Post{bid: uuid, visits: 5})
+
+      values = [%{bid: uuid, visits: 1}, %{bid: nil, visits: 1}, %{bid: uuid, visits: 3}]
+      types = %{bid: uuid_module, visits: :integer}
+
+      query =
+        from p in Post,
+          join: v in values(values, types),
+          on: p.visits == v.visits
+
+      assert {1, _} = TestRepo.delete_all(query)
+      assert TestRepo.all(Post) == [p2]
+    end
+
+    test "update_all" do
+      uuid_module = uuid_module(TestRepo.__adapter__())
+      uuid = uuid_module.generate()
+
+      TestRepo.insert!(%Post{bid: uuid, visits: 1})
+
+      values = [%{bid: uuid, visits: 10}, %{bid: nil, visits: 2}]
+      types = %{bid: uuid_module, visits: :integer}
+
+      query =
+        from p in Post,
+          join: v in values(values, types),
+          on: p.bid == v.bid,
+          update: [set: [visits: v.visits]]
+
+      assert {1, _} = TestRepo.update_all(query, [])
+      assert [%{visits: 10}] = TestRepo.all(Post)
+    end
+
+    defp uuid_module(Ecto.Adapters.Tds), do: Tds.Ecto.UUID
+    defp uuid_module(_), do: Ecto.UUID
+  end
 end

lib/ecto/query.ex

@@ -476,6 +476,59 @@ defmodule Ecto.Query do
     defstruct [:tag, :type, :value]
   end
 
+  defmodule Values do
+    @moduledoc false
+    defstruct [:types, :num_rows, :params]
+
+    def new(values_list, types) do
+      fields = fields(values_list)
+      types = types!(fields, types)
+      params = params!(values_list, types)
+      %__MODULE__{types: types, params: params, num_rows: length(values_list)}
+    end
+
+    defp fields(values_list) do
+      fields =
+        Enum.reduce(values_list, MapSet.new(), fn values, fields ->
+          Enum.reduce(values, fields, fn {field, _}, fields ->
+            MapSet.put(fields, field)
+          end)
+        end)
+
+      MapSet.to_list(fields)
+    end
+
+    defp types!(fields, types) do
+      Enum.map(fields, fn field->
+        case types do
+          %{^field => type} ->
+            {field, type}
+
+          _ ->
+            raise ArgumentError,
+                  "values/2 must declare the type for every field. " <>
+                    "The type was not given for field `#{field}`"
+        end
+      end)
+    end
+
+    defp params!(values_list, types) do
+      Enum.reduce(values_list, [], fn values, params ->
+        Enum.reduce(types, params, fn {field, type}, params ->
+          case values do
+            %{^field => value} ->
+              [{value, type} | params]
+
+            _ ->
+              raise ArgumentError,
+                    "each member of a values list must have the same fields. " <>
+                      "Missing field `#{field}` in #{inspect(values)}"
+          end
+        end)
+      end)
+    end
+  end
+
   @type t :: %__MODULE__{}
   @opaque dynamic_expr :: %DynamicExpr{}
 

lib/ecto/query/api.ex

@@ -502,6 +502,57 @@ defmodule Ecto.Query.API do
   """
   def splice(list), do: doc! [list]
 
+  @doc """
+  Creates a values list/constant table.
+
+  A values list can be used as a source in a query, both in `Ecto.Query.from/2`
+  and `Ecto.Query.join/5`.
+
+  The first argument is a list of maps representing the values of the constant table.
+  Each entry in the list must have exactly the same fields or an error is raised.
+
+  The second argument is a map of types corresponding to the fields in the first argument.
+  Each field must be given a type or an error is raised. Any type that can be specified in
+  a schema may be used.
+
+  ## Select example
+
+      values = [%{id: 1, text: "abc"}, %{id: 2, text: "xyz"}]
+      types = %{id: :integer, text: :string}
+
+      query =
+        from v1 in values(values, types),
+          join: v2 in values(values, types),
+          on: v1.id == v2.id
+
+      Repo.all(query)
+
+  ## Delete example
+      values = [%{id: 1, text: "abc"}, %{id: 2, text: "xyz"}]
+      types = %{id: :integer, text: :string}
+
+      query =
+        from p in Post,
+          join: v in values(values, types),
+          on: p.id == v.id,
+          where: p.counter == ^0
+
+      Repo.delete_all(query)
+
+  ## Update example
+      values = [%{id: 1, text: "abc"}, %{id: 2, text: "xyz"}]
+      types = %{id: :integer, text: :string}
+
+      query =
+        from p in Post,
+          join: v in values(values, types),
+          on: p.id == v.id,
+          update: [set: [text: v.text]]
+
+      Repo.update_all(query, [])
+  """
+  def values(values, types), do: doc! [values, types]
+
   @doc """
   Allows a field to be dynamically accessed.
 

lib/ecto/query/builder/from.ex

@@ -46,10 +46,17 @@ defmodule Ecto.Query.Builder.From do
 
   defp escape_source(query, env) do
     case Macro.expand_once(query, env) do
-      {:fragment, _, _} = fragment->
+      {:fragment, _, _} = fragment ->
         {fragment, {params, _acc}} = Builder.escape(fragment, :any, {[], %{}}, [], env)
         {fragment, Builder.escape_params(params)}
 
+      {:values, _, [values_list, types]} ->
+        prelude = quote do: values = Ecto.Query.Values.new(unquote(values_list), unquote(types))
+        types = quote do: values.types
+        num_rows = quote do: values.num_rows
+        params = quote do: Ecto.Query.Builder.escape_params(values.params)
+        {{:{}, [], [:values, [], [types, num_rows]]}, prelude, params}
+
       ^query ->
         case query do
           {left, right} -> {left, Macro.expand(right, env)}
@@ -111,6 +118,18 @@ defmodule Ecto.Query.Builder.From do
         {:ok, prefix} = prefix || {:ok, nil}
         {query(prefix, fragment, params, as, hints, env.file, env.line), binds, 1}
 
+      {{:{}, _, [:values, _, _]} = values, prelude, params} ->
+        {:ok, prefix} = prefix || {:ok, nil}
+        query = query(prefix, values, params, as, hints, env.file, env.line)
+
+        quoted =
+          quote do
+            unquote(prelude)
+            unquote(query)
+          end
+
+        {quoted, binds, 1}
+
       _other ->
         quoted =
           quote do

lib/ecto/query/builder/join.ex

@@ -15,57 +15,65 @@ defmodule Ecto.Query.Builder.Join do
   ## Examples
 
       iex> escape(quote(do: x in "foo"), [], __ENV__)
-      {:x, {"foo", nil}, nil, []}
+      {:x, {"foo", nil}, nil, nil, []}
 
       iex> escape(quote(do: "foo"), [], __ENV__)
-      {:_, {"foo", nil}, nil, []}
+      {:_, {"foo", nil}, nil, nil, []}
 
       iex> escape(quote(do: x in Sample), [], __ENV__)
-      {:x, {nil, Sample}, nil, []}
+      {:x, {nil, Sample}, nil, nil, []}
 
       iex> escape(quote(do: x in __MODULE__), [], __ENV__)
-      {:x, {nil, __MODULE__}, nil, []}
+      {:x, {nil, __MODULE__}, nil, nil, []}
 
       iex> escape(quote(do: x in {"foo", :sample}), [], __ENV__)
-      {:x, {"foo", :sample}, nil, []}
+      {:x, {"foo", :sample}, nil, nil, []}
 
       iex> escape(quote(do: x in {"foo", Sample}), [], __ENV__)
-      {:x, {"foo", Sample}, nil, []}
+      {:x, {"foo", Sample}, nil, nil, []}
 
       iex> escape(quote(do: x in {"foo", __MODULE__}), [], __ENV__)
-      {:x, {"foo", __MODULE__}, nil, []}
+      {:x, {"foo", __MODULE__}, nil, nil, []}
 
       iex> escape(quote(do: c in assoc(p, :comments)), [p: 0], __ENV__)
-      {:c, nil, {0, :comments}, []}
+      {:c, nil, {0, :comments}, nil, []}
 
       iex> escape(quote(do: x in fragment("foo")), [], __ENV__)
-      {:x, {:{}, [], [:fragment, [], [raw: "foo"]]}, nil, []}
+      {:x, {:{}, [], [:fragment, [], [raw: "foo"]]}, nil, nil, []}
 
   """
   @spec escape(Macro.t, Keyword.t, Macro.Env.t) :: {atom, Macro.t | nil, Macro.t | nil, list}
   def escape({:in, _, [{var, _, context}, expr]}, vars, env)
       when is_atom(var) and is_atom(context) do
-    {_, expr, assoc, params} = escape(expr, vars, env)
-    {var, expr, assoc, params}
+    {_, expr, assoc, prelude, params} = escape(expr, vars, env)
+    {var, expr, assoc, prelude, params}
   end
 
   def escape({:subquery, _, [expr]}, _vars, _env) do
-    {:_, quote(do: Ecto.Query.subquery(unquote(expr))), nil, []}
+    {:_, quote(do: Ecto.Query.subquery(unquote(expr))), nil, nil, []}
   end
 
   def escape({:subquery, _, [expr, opts]}, _vars, _env) do
-    {:_, quote(do: Ecto.Query.subquery(unquote(expr), unquote(opts))), nil, []}
+    {:_, quote(do: Ecto.Query.subquery(unquote(expr), unquote(opts))), nil, nil, []}
   end
 
   def escape({:fragment, _, [_ | _]} = expr, vars, env) do
     {expr, {params, _acc}} = Builder.escape(expr, :any, {[], %{}}, vars, env)
-    {:_, expr, nil, params}
+    {:_, expr, nil, nil, params}
+  end
+
+  def escape({:values, _, [values_list, types]}, _vars, _env) do
+    prelude = quote do: values = Ecto.Query.Values.new(unquote(values_list), unquote(types))
+    types = quote do: values.types
+    num_rows = quote do: values.num_rows
+    params = quote do: values.params
+    {:_, {:{}, [], [:values, [], [types, num_rows]]}, nil, prelude, params}
   end
 
   def escape({string, schema} = join, _vars, env) when is_binary(string) do
     case Macro.expand(schema, env) do
       schema when is_atom(schema) ->
-        {:_, {string, schema}, nil, []}
+        {:_, {string, schema}, nil, nil, []}
 
       _ ->
         Builder.error! "malformed join `#{Macro.to_string(join)}` in query expression"
@@ -77,19 +85,19 @@ defmodule Ecto.Query.Builder.Join do
     ensure_field!(field)
     var   = Builder.find_var!(var, vars)
     field = Builder.quoted_atom!(field, "field/2")
-    {:_, nil, {var, field}, []}
+    {:_, nil, {var, field}, nil, []}
   end
 
   def escape({:^, _, [expr]}, _vars, _env) do
-    {:_, quote(do: Ecto.Query.Builder.Join.join!(unquote(expr))), nil, []}
+    {:_, quote(do: Ecto.Query.Builder.Join.join!(unquote(expr))), nil, nil, []}
   end
 
   def escape(string, _vars, _env) when is_binary(string) do
-    {:_, {string, nil}, nil, []}
+    {:_, {string, nil}, nil, nil, []}
   end
 
   def escape(schema, _vars, _env) when is_atom(schema) do
-    {:_, {nil, schema}, nil, []}
+    {:_, {nil, schema}, nil, nil, []}
   end
 
   def escape(join, vars, env) do
@@ -147,8 +155,8 @@ defmodule Ecto.Query.Builder.Join do
     end
 
     {query, binding} = Builder.escape_binding(query, binding, env)
-    {join_bind, join_source, join_assoc, join_params} = escape(expr, binding, env)
-    join_params = Builder.escape_params(join_params)
+    {join_bind, join_source, join_assoc, join_prelude, join_params} = escape(expr, binding, env)
+    join_params = escape_params(join_params)
 
     join_qual = validate_qual(qual)
     validate_bind(join_bind, binding)
@@ -188,13 +196,22 @@ defmodule Ecto.Query.Builder.Join do
     ]
 
     on = ensure_on(on, join_assoc, join_qual, join_source, env)
-    query = build_on(on, join, as, query, binding, count_bind, env)
+    query = build_on(on, join_prelude, join, as, query, binding, count_bind, env)
     {query, binding, next_bind}
   end
 
-  def build_on({:^, _, [var]}, join, as, query, _binding, count_bind, env) do
+  defp escape_params(params) when is_list(params) do
+    Builder.escape_params(params)
+  end
+
+  defp escape_params(params) do
+    quote do: Builder.escape_params(unquote(params))
+  end
+
+  def build_on({:^, _, [var]}, join_prelude, join, as, query, _binding, count_bind, env) do
     quote do
       query = unquote(query)
+      unquote(join_prelude)
 
       Ecto.Query.Builder.Join.join!(
         query,
@@ -208,7 +225,7 @@ defmodule Ecto.Query.Builder.Join do
     end
   end
 
-  def build_on(on, join, as, query, binding, count_bind, env) do
+  def build_on(on, join_prelude, join, as, query, binding, count_bind, env) do
     case Ecto.Query.Builder.Filter.escape(:on, on, count_bind, binding, env) do
       {_on_expr, {_on_params, %{subqueries: [_ | _]}}} ->
         raise ArgumentError, "invalid expression for join `:on`, subqueries aren't supported"
@@ -218,6 +235,8 @@ defmodule Ecto.Query.Builder.Join do
 
         join =
           quote do
+            unquote(join_prelude)
+
             %JoinExpr{
               unquote_splicing(join),
               on: %QueryExpr{