title: Primary key for multiple columns in PostgreSQL?
body: <p>How to provide primary key for multiple column in a single table using PostgreSQL?   </p>
  
  <p>Example:</p>
  
  <pre><code>Create table "Test" 
  (
     "SlNo" int not null primary key,
     "EmpID" int not null, /* Want to become primary key */
     "Empname" varchar(50) null,
     "EmpAddress" varchar(50) null
  );
  </code></pre>
  
  <p>Note: I want to make <code>"EmpID"</code> also a primary key.</p>