In MySQL you can use HAVING, ORDER BY, and GROUP BY with column aliases but not WHERE: https://stackoverflow.com/questions/942571/using-column-alia...
In PostgreSQL you can not use the column alias within WHERE or HAVING but you can use it in ORDER BY and GROUP BY: https://dba.stackexchange.com/questions/225874/using-column-...
Similarly in Microsoft SQL server you cannot use it in WHERE, HAVING, or GROUP BY but you can use it in ORDER BY.
In SQLite you can use column aliases within WHERE, HAVING, ORDER BY and GROUP BY: https://stackoverflow.com/questions/10923107/using-a-column-...
In Google Bigquery you can use them in GROUP BY and ORDER BY but in Hive you can only use them in ORDER BY.
As far as I know the standard only defines that you cannot use column aliases in the WHERE clause. I'm sure someone else can chime in with what the standard says about column aliases in ORDER BY, GROUP BY and HAVING.