First, if someone has a better title please help.

If I have let's say a 'calendar' table with a 'day' column. And I have the following query:

```
SELECT day, day AS testDay, testDay AS test2Day FROM calendar

```

MySQL will complain that "testDay" is an unknown column. Of course you will tell me that this statement is useless, but my statement looks more like this:

```
SELECT day, SOME_CRAZY_EXPRESSION_OF(day) AS testDay, EXPRESSION_OF(testDay) AS test2Day FROM calendar

```

And the point is I don't want to evaluate twice the first expression to use it within the second expression.. So is there a way to use a value calculated in the select as part of the select itself?

Of course I could do:

```
SELECT day, SOME_CRAZY_EXPRESSION_OF(day) AS testDay, EXPRESSION_OF(SOME_CRAZY_EXPRESSION_OF(day)) AS test2Day FROM calendar

```

But I'm trying to avoid wasting. If I have no choice, that's what I'll do.