Support Ecto.Query.with_ties/3 (#471)

Author: greg-rychlewski

lib/ecto/adapters/myxql/connection.ex

@@ -463,7 +463,10 @@ if Code.ensure_loaded?(MyXQL) do
     end
 
     defp limit(%{limit: nil}, _sources), do: []
-    defp limit(%{limit: %QueryExpr{expr: expr}} = query, sources) do
+    defp limit(%{limit: %{with_ties: true}} = query, _sources) do
+      error!(query, "MySQL adapter does not support the `:with_ties` limit option")
+    end
+    defp limit(%{limit: %{expr: expr}} = query, sources) do
       [" LIMIT " | expr(expr, sources, query)]
     end
 

lib/ecto/adapters/postgres/connection.ex

@@ -594,7 +594,14 @@ if Code.ensure_loaded?(Postgrex) do
     end
 
     defp limit(%{limit: nil}, _sources), do: []
-    defp limit(%{limit: %QueryExpr{expr: expr}} = query, sources) do
+    defp limit(%{limit: %{with_ties: true}, order_bys: []} = query, _sources) do
+      error!(query, "PostgreSQL adapter requires an `order_by` clause if the " <>
+                    "`:with_ties` limit option is `true`")
+    end
+    defp limit(%{limit: %{expr: expr, with_ties: true}} = query, sources) do
+      [" FETCH FIRST ", expr(expr, sources, query) | " ROWS WITH TIES"]
+    end
+    defp limit(%{limit: %{expr: expr}} = query, sources) do
       [" LIMIT " | expr(expr, sources, query)]
     end
 

lib/ecto/adapters/tds/connection.ex

@@ -579,9 +579,13 @@ if Code.ensure_loaded?(Tds) do
 
     defp limit(%Query{limit: nil}, _sources), do: []
 
+    defp limit(%Query{limit: %{with_ties: true}} = query, _sources) do
+      error!(query, "Tds adapter does not support the `:with_ties` limit option")
+    end
+
     defp limit(
            %Query{
-             limit: %QueryExpr{
+             limit: %{
                expr: expr
              }
            } = query,

mix.lock

@@ -6,7 +6,7 @@
   "decimal": {:hex, :decimal, "2.0.0", "a78296e617b0f5dd4c6caf57c714431347912ffb1d0842e998e9792b5642d697", [:mix], [], "hexpm", "34666e9c55dea81013e77d9d87370fe6cb6291d1ef32f46a1600230b1d44f577"},
   "deep_merge": {:hex, :deep_merge, "0.2.0", "c1050fa2edf4848b9f556fba1b75afc66608a4219659e3311d9c9427b5b680b3", [:mix], [], "hexpm", "e3bf435a54ed27b0ba3a01eb117ae017988804e136edcbe8a6a14c310daa966e"},
   "earmark_parser": {:hex, :earmark_parser, "1.4.29", "149d50dcb3a93d9f3d6f3ecf18c918fb5a2d3c001b5d3305c926cddfbd33355b", [:mix], [], "hexpm", "4902af1b3eb139016aed210888748db8070b8125c2342ce3dcae4f38dcc63503"},
-  "ecto": {:git, "https://github.com/elixir-ecto/ecto.git", "9561024c0ae494b7c1d3d9822fa079f00b127fdd", []},
+  "ecto": {:git, "https://github.com/elixir-ecto/ecto.git", "ab0771ef7ea0825f0dadfe02bfbe04d946ca5f07", []},
   "ex_doc": {:hex, :ex_doc, "0.29.0", "4a1cb903ce746aceef9c1f9ae8a6c12b742a5461e6959b9d3b24d813ffbea146", [:mix], [{:earmark_parser, "~> 1.4.19", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "f096adb8bbca677d35d278223361c7792d496b3fc0d0224c9d4bc2f651af5db1"},
   "jason": {:hex, :jason, "1.4.0", "e855647bc964a44e2f67df589ccf49105ae039d4179db7f6271dfd3843dc27e6", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "79a3791085b2a0f743ca04cec0f7be26443738779d09302e01318f97bdb82121"},
   "makeup": {:hex, :makeup, "1.1.0", "6b67c8bc2882a6b6a445859952a602afc1a41c2e08379ca057c0f525366fc3ca", [:mix], [{:nimble_parsec, "~> 1.2.2 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "0a45ed501f4a8897f580eabf99a2e5234ea3e75a4373c8a52824f6e873be57a6"},

test/ecto/adapters/myxql_test.exs

@@ -441,6 +441,15 @@ defmodule Ecto.Adapters.MyXQLTest do
     assert all(query) == ~s{SELECT TRUE FROM `schema` AS s0 LIMIT 3 OFFSET 5}
   end
 
+  test "limit `:with_ties` option" do
+    msg = ~r"MySQL adapter does not support the `:with_ties` limit option"
+    query = Schema |> limit([r], 3) |> with_ties(true) |> select([], true) |> plan()
+
+    assert_raise Ecto.QueryError, msg, fn ->
+      all(query)
+    end
+  end
+
   test "lock" do
     query = Schema |> lock("LOCK IN SHARE MODE") |> select([], true) |> plan()
     assert all(query) == ~s{SELECT TRUE FROM `schema` AS s0 LOCK IN SHARE MODE}

test/ecto/adapters/postgres_test.exs

@@ -561,6 +561,18 @@ defmodule Ecto.Adapters.PostgresTest do
     assert all(query) == ~s{SELECT TRUE FROM "schema" AS s0 LIMIT 3 OFFSET 5}
   end
 
+  test "limit `:with_ties` option" do
+    query = Schema |> order_by([r], r.x) |> limit([r], 3) |> with_ties(true) |> select([], true) |> plan()
+    assert all(query) == ~s{SELECT TRUE FROM "schema" AS s0 ORDER BY s0."x" FETCH FIRST 3 ROWS WITH TIES}
+
+    msg = ~r"PostgreSQL adapter requires an `order_by` clause if the `:with_ties` limit option is `true`"
+    query = Schema |> limit([r], 3) |> with_ties(true) |> select([], true) |> plan()
+
+    assert_raise Ecto.QueryError, msg, fn ->
+      all(query)
+    end
+  end
+
   test "lock" do
     query = Schema |> lock("FOR SHARE NOWAIT") |> select([], true) |> plan()
     assert all(query) == ~s{SELECT TRUE FROM "schema" AS s0 FOR SHARE NOWAIT}

test/ecto/adapters/tds_test.exs

@@ -560,6 +560,15 @@ defmodule Ecto.Adapters.TdsTest do
     end
   end
 
+  test "limit `:with_ties` option" do
+    msg = ~r"Tds adapter does not support the `:with_ties` limit option"
+    query = Schema |> limit([r], 3) |> with_ties(true) |> select([], true) |> plan()
+
+    assert_raise Ecto.QueryError, msg, fn ->
+      all(query)
+    end
+  end
+
   test "lock" do
     query = Schema |> lock("NOLOCK") |> select([], true) |> plan()
     assert all(query) == ~s{SELECT CAST(1 as bit) FROM [schema] AS s0 OPTION (NOLOCK)}