migrations: add search_documents.unit_id unique constraint
A unique index is added to search_documents.unit_id. This will allow us
to add a FK in a later CL and provides another check for data in
search_documents.
Change-Id: I7681d7870bb4f2759da84fbd8131f5f692996cba
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/350252
Trust: Julie Qiu <julie@golang.org>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
diff --git a/migrations/000152_add_search_documents_unit_id_unique.down.sql b/migrations/000152_add_search_documents_unit_id_unique.down.sql
new file mode 100644
index 0000000..4a1e79c
--- /dev/null
+++ b/migrations/000152_add_search_documents_unit_id_unique.down.sql
@@ -0,0 +1,9 @@
+-- Copyright 2021 The Go Authors. All rights reserved.
+-- Use of this source code is governed by a BSD-style
+-- license that can be found in the LICENSE file.
+
+BEGIN;
+
+DROP INDEX search_documents_unit_id_key;
+
+END;
diff --git a/migrations/000152_add_search_documents_unit_id_unique.up.sql b/migrations/000152_add_search_documents_unit_id_unique.up.sql
new file mode 100644
index 0000000..4672cd5
--- /dev/null
+++ b/migrations/000152_add_search_documents_unit_id_unique.up.sql
@@ -0,0 +1,9 @@
+-- Copyright 2021 The Go Authors. All rights reserved.
+-- Use of this source code is governed by a BSD-style
+-- license that can be found in the LICENSE file.
+
+BEGIN;
+
+CREATE UNIQUE INDEX search_documents_unit_id_key ON search_documents(unit_id);
+
+END;
