title: Concat firstname and lastname with space in between in oracle pl sql
body: <p>I have one requirement to concat user first_ name, and last_name with space in between in Oracle.
  Ex: first_name is <code>'Hopkins'</code> and last_name is <code>'Joe'</code>.</p>
  
  <p>Full name should be printed as Hopkins Joe.</p>
  
  <p>I'm using Oracle 11g and it is working in SQL query, but not working in stored procedure.</p>