Use standard table name

legacy.yml

@@ -0,0 +1,13 @@
+---
+Name: silvershop-discounts-legacy
+---
+# Mapping rules to map old model-classes to new ones.
+SilverStripe\ORM\DatabaseAdmin:
+  classname_value_remapping:
+    Discount: SilverShop\Discounts\Model\Discount
+    GiftVoucherOrderItem: SilverShop\Discounts\Model\GiftVoucherOrderItem
+    OrderDiscountModifier: SilverShop\Discounts\Model\Modifiers\OrderDiscountModifier
+    OrderCoupon: SilverShop\Discounts\Model\OrderCoupon
+    OrderDiscount: SilverShop\Discounts\Model\OrderDiscount
+    PartialUseDiscount: SilverShop\Discounts\Model\PartialUseDiscount
+    SpecificPrice: SilverShop\Discounts\Model\SpecificPrice

src/Model/Discount.php

@@ -80,7 +80,7 @@ class Discount extends DataObject
 
     private static $default_sort = "EndDate DESC, StartDate DESC";
 
-    private static $table_name = 'Discount';
+    private static $table_name = 'SilverShop_Discount';
 
     protected $message;
 

src/Model/GiftVoucherOrderItem.php

@@ -20,7 +20,7 @@ class GiftVoucherOrderItem extends OrderItem
         "UnitPrice"
     ];
 
-    private static $table_name = 'GiftVoucherOrderItem';
+    private static $table_name = 'SilverShop_GiftVoucherOrderItem';
 
     /**
      * Don't get unit price from product

src/Model/Modifiers/OrderDiscountModifier.php

@@ -27,7 +27,7 @@ class OrderDiscountModifier extends OrderModifier
 
     private static $plural_name = "Discounts";
 
-    private static $table_name = 'OrderDiscountModifier';
+    private static $table_name = 'SilverShop_OrderDiscountModifier';
 
     public function value($incoming)
     {

src/Model/OrderCoupon.php

@@ -38,7 +38,7 @@ class OrderCoupon extends Discount
 
     private static $generated_code_length = 10;
 
-    private static $table_name = OrderCoupon::class;
+    private static $table_name = 'SilverShop_OrderCoupon';
 
     public static function get_by_code($code)
     {

src/Model/OrderDiscount.php

@@ -10,4 +10,6 @@
  */
 class OrderDiscount extends Discount
 {
+
+    private static $table_name = 'SilverShop_OrderDiscount';
 }

src/Model/PartialUseDiscount.php

@@ -27,7 +27,7 @@ class PartialUseDiscount extends Discount
 
     private static $plural_name = "Partial Use Discounts";
 
-    private static $table_name = 'PartialUseDiscount';
+    private static $table_name = 'SilverShop_PartialUseDiscount';
 
     public function getCMSFields($params = null)
     {

src/Model/SpecificPrice.php

@@ -43,7 +43,7 @@ class SpecificPrice extends DataObject
 
     private static $default_sort = "\"Price\" ASC";
 
-    private static $table_name = 'SpecificPrice';
+    private static $table_name = 'SilverShop_SpecificPrice';
 
     public static function filter(DataList $list, $member = null)
     {