PL/SQL Challenge 每日一题：2016-12-30 第三范式

A visitor shows an imprint work during an exposition of innovation in traditional craftsmanship of the east China's city of Hangzhou at Tiradentes Palace in Rio de Janeiro, Brazil, June 30, 2025. The event showcased a variety of Chinese traditional crafts and their innovative expressions to the Brazilian public through demonstrations and interactive experiences. (Xinhua/Wang Tiancong)

Guests communicate during an exposition of innovation in traditional craftsmanship of the east China's city of Hangzhou at Tiradentes Palace in Rio de Janeiro, Brazil, June 30, 2025. The event showcased a variety of Chinese traditional crafts and their innovative expressions to the Brazilian public through demonstrations and interactive experiences. (Xinhua/Wang Tiancong)

A visitor holds a handicraft featuring the archaeological ruins of Liangzhu, a UNESCO World Heritage site, during an exposition of innovation in traditional craftsmanship of the east China's city of Hangzhou at Tiradentes Palace in Rio de Janeiro, Brazil, June 30, 2025. The event showcased a variety of Chinese traditional crafts and their innovative expressions to the Brazilian public through demonstrations and interactive experiences. (Xinhua/Wang Tiancong)

Volunteers dressed in traditional Chinese attire showcase crafts featuring Chinese elements during an exposition of innovation in traditional craftsmanship of the east China's city of Hangzhou at Tiradentes Palace in Rio de Janeiro, Brazil, June 30, 2025. The event showcased a variety of Chinese traditional crafts and their innovative expressions to the Brazilian public through demonstrations and interactive experiences. (Xinhua/Wang Tiancong)