update migration with trigger on updated_at

Signed-off-by: Lykke Axlin <lykkeaxlin@hotmail.com>

Co-authored-by: klaraab <klarabroman@live.se>

plugins/bazaar-backend/migrations/20210923133459_trigger.js

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2021 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+exports.up = function (knex) {
+  return knex.raw(`
+        CREATE OR REPLACE FUNCTION update_timestamp() RETURNS TRIGGER
+        LANGUAGE plpgsql
+        AS
+        $$
+        BEGIN
+            NEW.updated_at = CURRENT_TIMESTAMP;
+            RETURN NEW;
+        END;
+        $$;
+      `);
+};
+
+exports.down = function (knex) {
+  return knex.raw(`
+        DROP FUNCTION IF EXISTS update_timestamp() CASCADE;
+      `);
+};

plugins/bazaar-backend/migrations/20210923133506_init.js

@@ -31,13 +31,17 @@ exports.up = async function setUpTables(knex) {
       .defaultTo('proposed')
       .notNullable()
       .comment('The status of the Bazaar project');
-    table
-      .dateTime('updated_at')
-      .defaultTo(knex.fn.now())
-      .notNullable()
-      .comment('The timestamp when this entry was updated');
+    table.timestamps(true, true);
   });
 
+  await knex.raw(`
+    CREATE TRIGGER update_timestamp
+    BEFORE UPDATE
+    ON metadata
+    FOR EACH ROW
+    EXECUTE PROCEDURE update_timestamp();
+  `);
+
   await knex.schema.createTable('members', table => {
     table.comment('The table of Bazaar members');
     table.text('entity_ref').notNullable().comment('The ref of the entity');