摘要： Description：Given a Weather table, write a SQL query to find all dates' Ids with higher temperature compared to its previous (yesterday's) dates. 选出比... 阅读全文

摘要： Discription：Write a SQL query to delete all duplicate email entries in a table named Person, keeping only unique emails based on its smallest Id. 删除重... 阅读全文

摘要： Description: Suppose that a website contains two tables, the Customers table and the Orders table. Write a SQL query to find all customers who never ... 阅读全文