Can I use column alias in SQL where clause?

Standard SQL doesn't allow you to refer to a column alias in a WHERE clause, except for GROUP BY, ORDER BY, or HAVING clauses.

--wrong

SELECT order_id, (order_price X 0.85) as discount_price from order where discount_price >=100;

Workaround 1, using subquery

select * from

(

  SELECT order_id, (order_price X 0.85) as discount_price from order

) x

order by discount_price >= 100;