老板想知道每样东西放在架上一共值多少钱。从 products 表里选出所有东西的 name，第二列是 price * stock（价格乘库存）。
| id | name | category | price | stock |
|---|---|---|---|---|
| 1 | Milk tea | drink | 12 | 30 |
| 2 | Lemon water | drink | 8 | 50 |
| 3 | Cheesecake | cake | 25 | 6 |
| 4 | Cookie | snack | 5 | 80 |
| 5 | Brownie | cake | 18 | 0 |
| 6 | Iced coffee | drink | 15 | 20 |
| 7 | Chips | snack | 7 | 40 |
| 8 | Fruit tart | cake | 28 | 4 |
| id | name | category | price | stock |
|---|---|---|---|---|
| 1 | Milk tea | drink | 12 | 30 |
| 2 | Lemon water | drink | 8 | 50 |
| 3 | Cheesecake | cake | 25 | 6 |
| 4 | Cookie | snack | 5 | 80 |
| 5 | Brownie | cake | 18 | 0 |
| 6 | Iced coffee | drink | 15 | 20 |
| 7 | Chips | snack | 7 | 40 |
| 8 | Fruit tart | cake | 28 | 4 |
-- 在这里写：第二列不是现成的列，是 price * stock 算出来的 SELECT name, price FROM products;
写好了先点「运行」看看结果，没问题再点「提交」。