fix ddl v2

dsolovianov/postgresql/DDL.sql

@@ -21,6 +21,8 @@ CREATE TABLE dsolovianov.orders (
     user_id		INT,
     order_date  TIMESTAMPTZ NOT NULL,
     status		VARCHAR(20)
+    CONSTRAINT orders_user_fk
+    	FOREIGN KEY (user_id) REFERENCES dsolovianov.users(id)
 );
 
 CREATE TABLE dsolovianov.order_items (
@@ -32,7 +34,5 @@ CREATE TABLE dsolovianov.order_items (
     CONSTRAINT order_items_order_fk
     	FOREIGN KEY (order_id) REFERENCES dsolovianov.orders(id),
     CONSTRAINT order_items_product_fk
-    	FOREIGN KEY (product_id) REFERENCES dsolovianov.products(id),
-    CONSTRAINT orders_user_fk
-    	FOREIGN KEY (user_id) REFERENCES dsolovianov.users(id)
+    	FOREIGN KEY (product_id) REFERENCES dsolovianov.products(id)
 );