宠物医院要给 Oslo 的老宠物寄体检提醒。只看主人 city 是 'Oslo' 的宠物，按 age 从大到小排，只要前 2 只。要宠物名、主人名、age 三列。
| id | name | city | phone |
|---|---|---|---|
| 1 | Lena | Oslo | 555-0101 |
| 2 | Marco | Rome | NULL |
| 3 | Priya | Oslo | 555-0103 |
| 4 | Omar | Cairo | NULL |
| 5 | Sofia | Rome | 555-0105 |
| id | name | kind | age | weight | owner_id |
|---|---|---|---|---|---|
| 1 | Biscuit | dog | 3 | 12 | 1 |
| 2 | Mochi | cat | 5 | 4 | 1 |
| 3 | Pepper | dog | 8 | 20 | 2 |
| 4 | Nemo | fish | 1 | NULL | 3 |
| 5 | Luna | cat | 2 | 3 | 3 |
| 6 | Rex | dog | 11 | 30 | NULL |
| 7 | Kiwi | bird | 4 | NULL | 5 |
| 8 | Tofu | cat | 7 | 5 | NULL |
| id | name | city | phone |
|---|---|---|---|
| 1 | Lena | Oslo | 555-0101 |
| 2 | Marco | Rome | NULL |
| 3 | Priya | Oslo | 555-0103 |
| 4 | Omar | Cairo | NULL |
| 5 | Sofia | Rome | 555-0105 |
| id | name | kind | age | weight | owner_id |
|---|---|---|---|---|---|
| 1 | Biscuit | dog | 3 | 12 | 1 |
| 2 | Mochi | cat | 5 | 4 | 1 |
| 3 | Pepper | dog | 8 | 20 | 2 |
| 4 | Nemo | fish | 1 | NULL | 3 |
| 5 | Luna | cat | 2 | 3 | 3 |
| 6 | Rex | dog | 11 | 30 | NULL |
| 7 | Kiwi | bird | 4 | NULL | 5 |
| 8 | Tofu | cat | 7 | 5 | NULL |
SELECT pets.name, owners.name, pets.age FROM pets JOIN owners ON pets.owner_id = owners.id -- 在这里写：WHERE 留下 Oslo 的，按 pets.age 从大到小，LIMIT 2 ;
写好了先点「运行」看看结果，没问题再点「提交」。