Update Flightlog.php

models/Flightlog.php

@@ -31,6 +31,7 @@ class Flightlog extends \yii\db\ActiveRecord
         return [
             [['registration_number', 'total_flight_hours'], 'required'],
             [['registration_number'], 'integer'],
+             [['registration_number'], 'unique','message' => 'This aircarft details is already saved please update'],
             [['total_flight_hours'], 'string', 'max' => 55],
             [['registration_number'], 'exist', 'skipOnError' => true, 'targetClass' => Aircraft::className(), 'targetAttribute' => ['registration_number' => 'id']],
         ];