title: A column in a table is referred to by multiple physical column names
body: <p>I have a spring boot project using JPA, So I am trying to map two tables into a third one using their Id :
  for example I have a coupon class, I have a customer class I want to take customer id and coupon id into a third table.</p>
  
  <p>I have coupons:</p>
  
  <pre><code>@Entity
  @Table(name = "coupons")
  public class Coupon {
  
      @Id
      @GeneratedValue(strategy = GenerationType.IDENTITY)
  
      private long coup_id;
      private String title;
      private String start;
      private String end; 
      private int amount; 
      private String type;
      private String message; 
      private double price;
      private String image;
  
      @ManyToMany(mappedBy = "coupons")
      private List&lt;Customer&gt; customers;
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/ZLxGr.png" rel="noreferrer"><img src="https://i.stack.imgur.com/ZLxGr.png" alt="enter image description here"></a></p>
  
  <p>I have customers:</p>
  
  <pre><code>@Entity
  @Table(name="customers")
  public class Customer {
  
      @Id
      @GeneratedValue(strategy=GenerationType.IDENTITY)
  
      private int cust_id;
  
      @Size(min=1,message="is required")
      private String cust_name;
  
      @Size(min = 1, message = "is required")
      private String password;
       @ManyToMany(cascade = { CascadeType.ALL })
          @JoinTable(
              name = "customer_coupon", 
              joinColumns = { @JoinColumn(name = "cust_id") }, 
              inverseJoinColumns = { @JoinColumn(name = "coup_id") }
          )
      private List&lt;Coupon&gt; coupons;
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/Fwm1t.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Fwm1t.png" alt="enter image description here"></a></p>
  
  <p>and I have the connecting table customer_coupon:</p>
  
  <p><a href="https://i.stack.imgur.com/Xo5jS.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Xo5jS.png" alt="enter image description here"></a></p>
  
  <p>This is the error I am getting when starting the project:</p>
  
  <pre><code>Caused by: org.hibernate.DuplicateMappingException: Table [coupons] contains physical column name [coup_id] referred to by multiple physical column names: [coupId], [coup_id]
  </code></pre>
  
  <p>I have no idea where it comes from, would love if someone could help me !</p>