再會，
我對 MySQL 還很陌生，我一直在研究它。我一直在關注一個使用 5.X 版的非常古老的教程。我在我的虛擬機上使用 8.0.29 版。使用示例世界資料庫，我在使用下面的查詢按大陸分組時遇到問題。
SELECT Continent, Region, SUM(Popuilation) AS TotalPop FROM country GROUP BY Contient, Region;
--------------- --------------------------- ------------
| Continent | Region | TotalPop |
--------------- --------------------------- ------------
| North America | Caribbean | 38140000 |
| Asia | Southern and Central Asia | 1490776000 |
| Africa | Central Africa | 95652000 |
| Europe | Southern Europe | 144674200 |
| Asia | Middle East | 188380700 |
| South America | South America | 345780000 |
| Oceania | Polynesia | 633050 |
| Antarctica | Antarctica | 0 |
| Oceania | Australia and New Zealand | 22753100 |
| Europe | Western Europe | 183247600 |
| Africa | Eastern Africa | 246999000 |
| Africa | Western Africa | 221672000 |
| Europe | Eastern Europe | 307026000 |
| North America | Central America | 135221000 |
| North America | North America | 309632000 |
| Asia | Southeast Asia | 518541000 |
| Africa | Southern Africa | 46886000 |
| Asia | Eastern Asia | 1507328000 |
| Europe | Nordic Countries | 24166400 |
| Africa | Northern Africa | 173266000 |
| Europe | Baltic Countries | 7561900 |
| Oceania | Melanesia | 6472000 |
| Oceania | Micronesia | 543000 |
| Europe | British Islands | 63398500 |
| Oceania | Micronesia/Caribbean | 0 |
--------------- --------------------------- ------------
25 rows in set (0.00 sec)
我做錯了什么？VTC 教程顯示大陸被很好地分組。
我真的為我在這個話題上的菜鳥提前道歉......
uj5u.com熱心網友回復：
您的查詢是正確的，除了Contient. 但是，如果您希望按照大洲對結果集進行排序，則必須在查詢中添加 order by 子句。
SELECT Continent, Region, SUM(Population) as TotalPop
FROM country
GROUP BY Continent, Region
ORDER BY Continent, Region;
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