在Hive中執行復雜查詢和子查詢可以通過使用HiveQL語言來實現。HiveQL語言類似于SQL，可以用于編寫復雜的查詢語句。
以下是一些示例復雜查詢和子查詢的示例：
SELECT product_name
FROM products
WHERE product_id = (
SELECT product_id
FROM sales
GROUP BY product_id
ORDER BY sum(sales_amount) DESC
LIMIT 1
);
SELECT department_name, sum(sales_amount) as total_sales
FROM sales
JOIN departments ON sales.department_id = departments.department_id
GROUP BY department_name;
SELECT
product_name,
CASE
WHEN sales_amount < 1000 THEN 'Low'
WHEN sales_amount >= 1000 AND sales_amount < 5000 THEN 'Medium'
ELSE 'High'
END AS sales_category
FROM sales;
這些示例展示了如何在Hive中使用復雜查詢和子查詢來處理數據。通過結合不同的查詢技巧，您可以執行各種復雜的數據分析和處理操作。
