dropColumn('comment', 'service_id'); $this->addColumn('comment', 'entity', $this->string()); $this->addColumn('comment', 'entity_id', $this->integer()); } /** * {@inheritdoc} */ public function safeDown() { echo "m180605_072337_alter_table_comment cannot be reverted.\n"; return false; } /* // Use up()/down() to run migration code without a transaction. public function up() { } public function down() { echo "m180605_072337_alter_table_comment cannot be reverted.\n"; return false; } */ }