title: SQL, On delete cascade and on update cascade
body: <p>I am new to SQL and I encountered a weird problem. So I have two tables OFFERS and
  SUPPLIER. Here is the Supplier table.</p>
  
  <pre><code>CREATE TABLE  "SUPPLIER" 
     (    "S#" NUMBER, 
      "NAME" VARCHAR2(50),  
      "CITY" VARCHAR2(50), 
       PRIMARY KEY ("S#") ENABLE
     )
  </code></pre>
  
  <p>And here is the OFFERS table.</p>
  
  <pre><code>CREATE TABLE  "OFFERS" 
     (    "P#" NUMBER, 
      "S#" NUMBER, 
      "V#" NUMBER, 
      "PR#" NUMBER, 
        CONSTRAINT "PK_OFFERS" PRIMARY KEY ("P#") ENABLE
     )
  </code></pre>
  
  <p>So now, when I try to add a Foreign key constraint to the offers table like this</p>
  
  <pre><code>ALTER TABLE OFFERS
  ADD CONSTRAINT FK_SUPPLIERS FOREIGN KEY(S#)
   REFERENCES SUPPLIER (S#) 
  ON DELETE CASCADE
  ON UPDATE CASCADE
  </code></pre>
  
  <p>I get an error saying : "ORA-01735: invalid ALTER TABLE option". If I remove the last line, which is "ON UPDATE CASCADE" this works perfectly fine. So, what am I doing wrong? I've seen a lot of examples like this on the internet, that are supposed to work, so I am kinda confused. I am working on apex.oracle.com if that makes any difference.</p>