Question

    create users (id, gender, name, birth_date, married_on, died_on, ..)
    create user_relationships (id, user_id1, user_id2, relationship_type)

users (1, "M", "John", ..)
users (2, "F", "Mary", ..)
user_relationships (1, 1, 2, "married-to")

我该如何查询以下内容？

a. Users who are celebrating their birthdays next week.
b. Users whose marriage dates falling on the next week (Output should include Mr & Mrs John)
c. Users who died, the same time next week.

Answer 1

下周庆祝生日的用户。

一种方法是看他们一个星期的年龄是否大于他们今天的年龄：

SELECT *
FROM   users
WHERE  TIMESTAMPDIFF(YEAR, birth_date, CURRENT_DATE + INTERVAL 1 WEEK) >
       TIMESTAMPDIFF(YEAR, birth_date, CURRENT_DATE)

结婚日期在下周的用户。

类似地：

SELECT *
FROM   users
WHERE  TIMESTAMPDIFF(YEAR, married_on, CURRENT_DATE + INTERVAL 1 WEEK) >
       TIMESTAMPDIFF(YEAR, married_on, CURRENT_DATE)

死亡的用户，下周同一时间。

我会留下这个作为读者的练习。

如何查询与婚姻/死亡日期相关的信息

1 个答案: