MySQL练习-温故而知新，再见恍若隔世

175. 组合两个表

select firstname, lastname, city, state
from person left join Address
on person.PersonId = Address.PersonId
;

181. 超过经理收入的员工

SELECT
    a.Name AS 'Employee'
FROM
    Employee AS a,
    Employee AS b
WHERE
    a.ManagerId = b.Id
        AND a.Salary > b.Salary
;

182. 查找重复的电子邮箱

select Email from
(
    select Email, count(Email) as num
    from Person
    group by Email
)  as statistic
where num > 1;

183. 从不订购的客户

select customers.name as 'Customers'
from customers
where customers.id not in 
(
    select customerid from orders
)
;

196. 删除重复的电子邮箱

delete p1 from person p1, person p2
where p1.email = p2.email and p1.id > p2.id

197. 上升的温度

select 
    weather.id as 'id'
from weather join weather w on DATEDIFF(weather.recordDate, w.recordDate) = 1
    and weather.Temperature > w.Temperature
;