entc/integration: add edges-only index

Summary: Pull Request resolved: https://github.com/facebookincubator/ent/pull/153

Reviewed By: idoshveki

Differential Revision: D18419861

fbshipit-source-id: af7a07eacc601d0db54a5512f6edf26d725f5f7e

entc/integration/ent/migrate/schema.go

@@ -133,6 +133,11 @@ var (
 				Unique:  true,
 				Columns: []*schema.Column{FilesColumns[2], FilesColumns[3]},
 			},
+			{
+				Name:    "owner_id_type_id",
+				Unique:  false,
+				Columns: []*schema.Column{FilesColumns[7], FilesColumns[5]},
+			},
 			{
 				Name:    "name_owner_id_type_id",
 				Unique:  true,

entc/integration/ent/schema/file.go

@@ -54,6 +54,8 @@ func (File) Indexes() []ent.Index {
 		// unique index prevents duplicates records.
 		index.Fields("name", "user").
 			Unique(),
+		// index on edges only.
+		index.Edges("owner", "type"),
 		// unique index under the "owner" sub-tree.
 		// user/owner can't have files with duplicate names.
 		index.Fields("name").