title: How to do same thing on multiple conflicts in PostgreSQL?
body: <p>For example if I have a table:</p>
  
  <pre><code>create table test(
  
      username                varchar(50)   PRIMARY KEY,      
      customer                varchar(12),
      nickname                varchar(12)  
  );
  
  create unique index unique_customer_nickname on test(customer,nickname);
  </code></pre>
  
  <p>Therefore username is unique and (customer,nickname) together are unique.</p>
  
  <p>Then If I want to write an upsert statement like this:</p>
  
  <pre><code>Insert into test(username,customer,nickname) values('utest','ctest','ntest') 
  on conflict(username) or on conflict(customer,nickname) DO UPDATE ....
  </code></pre>
  
  <p>but this gives me syntax error.
  I also tried <code>on (conflict(username) or conflict(customer,nickname))</code> 
  but this also returns a syntax error.</p>
  
  <p>so what I want is for different conflicts to perform the same thing.</p>