LUCKYOJ

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 abov

Now we’ve got two table. One customer table for customerid and their names, One Order tablefor customers’ Id that bought something. We will find the customers that in the customer table but not in ord

Leetcode : Duplicate EmailsWrite 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 | +—-+———+

The Employee table holds all employees. Every employee has an Id, a salary, and there is also a column for the department Id.+—-+——-+——–+————–+ | Id | Name | Salary | DepartmentId | +—-+——-+——–+————

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 |

Leetcode : Employees Earning More Than Their Managers+—-+——-+——–+———–+ | Id | Name | Salary | ManagerId | +—-+——-+——–+———–+ | 1 | Joe | 70000 | 3 | | 2 | Henry | 80000 | 4 |

Write a SQL query to rank scores. If there is a tie between two scores, both should have the same ranking. Note that after a tie, the next ranking number should be the next consecutive integer value. I