数据，开发和AI的专栏

题目如下 Write a SQL query to get the second highest salary from the Employee table. Id Salary 1 100 2 200 3 300 For example, given the above Employee table, the second highest s

用户旅行的题目如下 The Trips table holds all taxi trips. Each trip has a unique Id, while Client_Id and Driver_Id are both foreign keys to the Users_Id at the Users table. Status is an ENUM type of (‘complete

题目如下: Write a SQL query to find all numbers that appear at least three times consecutively. Id Num 1 1 2 1 3 1 4 2 5 1 6 2 7 2 For example, given the above Lo

题目如下 Suppose that a website contains two tables, the Customers table and the Orders table. Write a SQL query to find all customers who never order anything. Table: Customers. Id Name

题目如下 The Employee table holds all employees including their managers. Every employee has an Id, and there is also a column for the manager Id. Id Name Salary ManagerId 1 Joe 70000

重复邮件 Write a SQL query to find all duplicate emails in a table named Person. Id Email 1 a@b.com 2 c@d.com 3 a@b.com For example, your query should return the following for th