如何将人们分为年龄段，给定出生年份（SQL）

Question

鉴于birthing_year和personal_id，我想创建var“ age”，然后将personal_id分组为截至2018年的年龄段（范围）。

我尝试过的事情：

SELECT personal_id, (2018 - birth_year) AS age
FROM mydatabase
WHERE birth_year is not null
GROUP BY CASE
    WHEN age between 18 and 24 THEN '18-24'
    WHEN age between 25 and 34 THEN '25-34'
    WHEN age between 35 and 44 THEN '35-44'
    WHEN age between 45 and 54 THEN '45-54'
    WHEN age between 55 and 64 THEN '55-64'
    WHEN age > 64 THEN '65+'
    END

我收到一个错误消息，说“年龄”不是列名。我假设CASE语句可能需要嵌套，如下所示：

SELECT personal_id
FROM
(SELECT personal_id, (2018 - birth_year) as age,
CASE
    WHEN age between 18 and 24 THEN '18-24'
    WHEN age between 25 and 34 THEN '25-34'
    WHEN age between 35 and 44 THEN '35-44'
    WHEN age between 45 and 54 THEN '45-54'
    WHEN age between 55 and 64 THEN '55-64'
    WHEN age > 64 THEN '65+'
ELSE 0
END AS age_group
FROM mydatabase
).

这背后的理想选择是先创建“年龄”变量，然后再进行分类。

我希望这足够清楚。谢谢！

Answer 1

使用APPLY：

Answer 2

不允许使用内联别名