How to solve SP2-0552: Bind variable not declared?
<p>When I run this PL/SQL block:</p>

<pre><code>SQL&gt; set serveroutput on
SQL&gt; declare
  2  v_max_sal NUMBER(20)
  3  begin
  4  select max(sal) INTO :v_max_sal
  5  from emp e, dept d
  6  where e.deptno=d.deptno
  7  and d.dname='SALES';
  8  END;
  9  /
</code></pre>

<p>it throws to me the next error: <code>SP2-0552: Bind variable "V_MAX_SAL" not declared.</code> What am I missing or doing wrong?</p>