在在線職業(yè)教育培訓領域中，SQL語句用于獲取各種有用的數(shù)據(jù)。你用它來查詢哪些課程最受歡迎，哪些學生的學習進度最快，或者哪些教師的教學效果最好等等。

`SELECT course_name, COUNT(*) AS student_count FROM enrollment GROUP BY course_name ORDER BY student_count DESC LIMIT ;`

`SELECT user_id, AVG(progress) AS avg_progress FROM progress_report GROUP BY user_id ORDER BY avg_progress DESC LIMIT ;`

`SELECT teacher_id, AVG(rating) AS avg_rating FROM teaching_review GROUP BY teacher_id ORDER BY avg_rating DESC LIMIT ;`

在游戲電競領域中，SQL語句用來追蹤玩家的表現(xiàn)，分析比賽結(jié)果，甚至預測未來的比賽走勢。你用它來查詢某個玩家的歷史成績，或者計算某個隊伍的勝率等等。

`SELECT game_date, score FROM game_result WHERE player_id = ? ORDER BY game_date ASC;`

`SELECT team_id, COUNT(CASE WHEN result = 'win' THEN END) / COUNT(*) * AS win_rate FROM game_record GROUP BY team_id;`

在化學制品領域中，SQL語句用來管理庫存，跟蹤訂單，以及進行數(shù)據(jù)分析等。你用它來查詢某種產(chǎn)品的庫存量，或者找出銷售額最高的產(chǎn)品等等。

`SELECT product_code, SUM(stock_quantity) AS total_stock FROM inventory WHERE product_code = ?;`

`SELECT product_code, SUM(sales_amount) AS total_sales FROM sales_record GROUP BY product_code ORDER BY total_sales DESC LIMIT ;`

在礦泉水領域中，SQL語句用來管理供商信息，監(jiān)控銷售情況，以及進行市場分析等。你用它來查詢某個地區(qū)的銷售數(shù)據(jù)，或者找出最受歡迎的品牌等等。

`SELECT region_code, SUM(units_sold) AS total_units FROM sales_report WHERE region_code = ?;`