title: PL SQL - convert a numerical value into varchar (percent)
body: <p>I have a query that uses the outputs(R1,R2) of two sub queries in order to divide them:</p>
  
  <pre><code>select a.R1/b.R2*100.0 as Result
  from
  (query1) a,
  (query2) b
  </code></pre>
  
  <p>The division's output is a (decimal) number as well as the R1,R2 outputs.</p>
  
  <p>I want to add to the Result the '%' sign, (i.e 10,75 %), but using a solution like the below one, returns an error 01722=invalid number</p>
  
  <pre><code>select cast(cast(a.R1/b.R2*100.0 as decimal(10,2)) as varchar(10)) + '%' as Result
  from
  (query1) a,
  (query2) b
  </code></pre>