Using User-Defined Variables
You can employ MySQL user variables to remember results without having to store them in temporary
variables in the client. (See Section 9.4, “User-Defined Variables”.)
For example, to find the articles with the highest and lowest price you can do this:
mysql SELECT @min_price:=MIN(price),@max_price:=MAX(price) FROM shop;
mysql SELECT * FROM shop WHERE price=@min_price OR price=@max_price;
+---------+--------+-------+
| article | dealer | price |
+---------+--------+-------+
| 0003 | D | 1.25 |
| 0004 | D | 19.95 |
+---------+--------+-------+
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