title: Hashing string in Oracle
body: <p>I know there's a function to obtain the hash value from a varchar in Oracle, but when I run the query to see the returned value it sends the following message.</p>
  
  <pre><code>ORA-00904: : identificador no válido
  00904. 00000 -  "%s: invalid identifier"
  *Cause:    
  *Action:
  Error en la línea: 70, columna: 7
  </code></pre>
  
  <p>What I'm doing is the following:</p>
  
  <pre><code>select DBMS_CRYPTO.hash(utl_raw.cast_to_raw('Foo'), 3) FROM dual;
  </code></pre>
  
  <p>It should return the SHA-1 of the string.</p>