title: How to insert columns with adding sequence column?
body: <p>In an Oracle database (11gR2), I have a table <code>my_table</code> with columns (<em>sequence</em>, <em>col1</em>, <em>col2</em>, <em>col3</em>). I want to insert values into the table that are queried from other tables, i.e. <code>insert into my_table select &lt;query from other tables&gt;</code>. The problem is that the primary key is the four columns, hence I need to add a sequence starting from 0 up till the count of the rows to be inserted (order is not a problem).</p>
  
  <p>I tried using a loop like this:</p>
  
  <pre><code>DECLARE
      j    NUMBER;
      r_count number;
  BEGIN
      select count(1) into r_count from &lt;my query to be inserted&gt;;
      FOR j IN 0 .. r_count
      LOOP
          INSERT INTO   my_table
                select &lt;my query, incorporating r_count as sequence column&gt; ;
      END LOOP;
  END;
  </code></pre>
  
  <p>But it didn't work, actually looped <code>r_count</code> times trying to insert the entire rows every time, as logically it shall do. How can I achieve the expected goal and insert rows with adding a sequence column?</p>