added history of changes

console/migrations/m200729_104128_create_change_history_table.php

@@ -0,0 +1,40 @@
+<?php
+
+use yii\db\Migration;
+
+/**
+ * Handles the creation of table `{{%change_history}}`.
+ */
+class m200729_104128_create_change_history_table extends Migration
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function safeUp()
+    {
+        $tableOptions = null;
+        if ($this->db->driverName === 'mysql') {
+            // http://stackoverflow.com/questions/766809/whats-the-difference-between-utf8-general-ci-and-utf8-unicode-ci
+            $tableOptions = 'CHARACTER SET utf8 COLLATE utf8_unicode_ci ENGINE=InnoDB';
+        }
+
+        $this->createTable('{{%change_history}}', [
+            'id' => $this->primaryKey(),
+            'type' => $this->string(255),
+            'type_id' => $this->integer(),
+            'field_name' => $this->string(255),
+            'label' => $this->string(255),
+            'old_value' => $this->string(255),
+            'new_value' => $this->string(255),
+            'created_at' => $this->dateTime(),
+        ], $tableOptions);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function safeDown()
+    {
+        $this->dropTable('{{%change_history}}');
+    }
+}