Checkpoint: dziala sprawdzanie values in the exchanges/exchange

Signed-off-by: Marcin Woźniak <y0rune@aol.com>

buisnesslogic/src/main/java/com/plannaplan/entities/Exchange.java

@@ -4,6 +4,8 @@ import javax.persistence.Entity;
 import javax.persistence.GeneratedValue;
 import javax.persistence.GenerationType;
 import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.OneToOne;
 
 @Entity
 public class Exchange {
@@ -12,8 +14,16 @@ public class Exchange {
     @GeneratedValue(strategy = GenerationType.AUTO)
     private Long id;
 
+    @OneToOne
+    @JoinColumn(name = "trader_id")
     private User trader;
+
+    @OneToOne
+    @JoinColumn(name = "owned_id")
     private Assignment ownedAssignment;
+   
+    @OneToOne
+    @JoinColumn(name = "desired_id")
     private Groups desiredAssignment;
     
     public Exchange() {