title: PostgreSQL encrypt function not found
body: <p>I'm new to PostgreSQL. I've read from the tutorial. I  can successfully <code>SELECT</code>, <code>INSERT</code>, <code>DELETE</code> and <code>UPDATE</code> the data(I know this is just a basic part). </p>
  
  <p>My problem now is to encrypt the data. I'm searching now for tutorial, but I failed to find the answer of my question. I try this code in "execute arbitrary SQL" (edit: in PgAdmin-III? Some other tool?).</p>
  
  <pre><code>INSERT INTO "admin" ("email_address", "password", "role_type", "status") 
  VALUES ('encrypt(''sdf'', digest(''secret2'', ''sha256''), ''aes'') ', 'sd', 'admin', 'Active')
  </code></pre>
  
  <p>but the result I get is this</p>
  
  <pre><code>ERROR: function encrypt(unknown, unknown) does not exist
  </code></pre>
  
  <p>How can I get this function? </p>
  
  <p>So far, as what I have read, they only show code how to use it.</p>