Discussion on: What code snippets do you use?

case 
   when regexp_like(CUSTOMER_EMAIL_ADDRESS, '^[A-Za-z0-9_-]+(\.[A-Za-z0-9_-]+)*@[A-Za-z0-9_-]+(\.[A-Za-z0-9_-]+)*\.([a-z]{2,4})$') 
   then CUSTOMER_EMAIL_ADDRESS
   else null 
end as "EMAIL_ADDRESS"

update
 TABLE
set
  DATE_COLUMN = TO_DATE(TRUNC(DBMS_RANDOM.value(TO_CHAR(date '2018-03-06','J'),TO_CHAR(CURRENT_TIMESTAMP,'J'))),'J');