SQL 从出生日期起按年龄对学生进行分组

Question

我有一个 table "student"，其中包含学生的 "name" 和 "DOB"。

我想将学生分为以下几组：

一个。 10-12
b. 13-14
C。 15-16 d. >= 17

所以它会出现

一个。保罗，彼得玛丽
b.约翰、威廉
等等

我该怎么做？

到目前为止我有：

 select  case
            when  age between 10 and 12 then a
            when  age between 13 and 14 then b
            when  age between 15 and 16 then c
            when  age >= 17 then d

    from    (
            SELECT  ROUND(DATEDIFF(Cast(CURRENT_TIMESTAMP() as Date),
                        Cast(birthday as Date)) / 365, 0) as age
            FROM    db.student

但似乎无法理解它。

我正在使用 Management Studio。

非常感谢。

Answer 1

以下查询可能会为您提供所需的结果。首先，年龄是确定的。（我在 DATEDIFF 函数中添加了日期格式 - 日 -）。然后，确定年龄段。

WITH ages AS
(
SELECT
    name,
    ROUND(DATEDIFF(day, Cast(CURRENT_TIMESTAMP() as Date), Cast(birthday as Date)) / 365, 0) as age
FROM db.student
)
SELECT
    name,
    case
                    when  age between 10 and 12 then a
                    when  age between 13 and 14 then b
                    when  age between 15 and 16 then c
                    when  age >= 17 then d
    end as age_category
FROM ages
ORDER BY name;

SQL 从出生日期起按年龄对学生进行分组

SQL group students by age from date of birth

sql

sql-server

datediff