考虑到birth_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“ age”不是列名。我假设CASE语句可能需要嵌套,就像这样:
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
).
理想的方法是先创建“年龄”变量,然后再进行分类。
我希望这足够清楚。谢谢!
答案 0 :(得分:0)
使用APPLY
:
SELECT agegrp, COUNT(*)
FROM mydatabase d CROSS APPLY
(VALUES (2018 - birth_year)) v1(age) CROSS APPLY
(VALUES (CASE WHEN v1.age between 18 and 24 THEN '18-24'
WHEN v1.age between 25 and 34 THEN '25-34'
WHEN v1.age between 35 and 44 THEN '35-44'
WHEN v1.age between 45 and 54 THEN '45-54'
WHEN v1.age between 55 and 64 THEN '55-64'
WHEN v1.age > 64 THEN '65+'
END)
) v(agegrp)
WHERE birth_year is not null
GROUP BY agegrp;
我将您的查询更改为聚合查询,这样才有意义。
答案 1 :(得分:0)
不允许使用内联别名
SELECT personal_id, CASE
WHEN (2018 - birth_year) between 18 and 24 THEN '18-24'
WHEN (2018 - birth_year) between 25 and 34 THEN '25-34'
WHEN (2018 - birth_year) between 35 and 44 THEN '35-44'
WHEN (2018 - birth_year) between 45 and 54 THEN '45-54'
WHEN (2018 - birth_year) between 55 and 64 THEN '55-64'
WHEN (2018 - birth_year) > 64 THEN '65+' AS age_grop
FROM mydatabase
WHERE birth_year is not null
GROUP BY CASE
WHEN (2018 - birth_year) between 18 and 24 THEN '18-24'
WHEN (2018 - birth_year) between 25 and 34 THEN '25-34'
WHEN (2018 - birth_year) between 35 and 44 THEN '35-44'
WHEN (2018 - birth_year) between 45 and 54 THEN '45-54'
WHEN (2018 - birth_year) between 55 and 64 THEN '55-64'
WHEN (2018 - birth_year) > 64 THEN '65+'
END,personal_id