DROP TABLE table_name;
執行後,**資料表結構與所有資料永久刪除**,無法復原。與 DELETE 或 TRUNCATE 不同:後兩者保留表格結構(欄位定義、索引、約束等)。
DROP TABLE employee;
使用資料表別名簡化多表查詢:
SELECT A1.store_name AS Store, SUM(Sales) AS "Total Sales"
FROM Store_Information A1
GROUP BY A1.store_name;
結果:
| Store | Total Sales |
|---|---|
| Los Angeles | $1800 |
| San Diego | $250 |
| Boston | $700 |