MYSQL database select issue
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I m try to do something like that:

    Select column_name*other_column_name as sqr from table where sqr<25 Order by(sqr)

column_name and column_name are columns of my database where I store int values.

I find that 

Standard SQL doesn't allow you to refer to a column alias in a WHERE clause. This restriction is imposed because when the WHERE code is executed, the column value may not yet be determined. For example, the following query is illegal.

does anybody Know how to get through in a polite way, please don't say that:

    Select column_name*other_column_name as sqr from table where column_name*other_column_name<25 order by (column_name*other_column_name); 

becouse in this example I simplify the equations but in my proyect the equation is really long 

thanks sorry for my english