SQL为返回的年龄段创建存储过程

Question

我有一个名为Person的表，其中包含一个名为PersonAge的字段。 我需要按年龄段对年龄进行分组，即'12及以下'，'13 -17'，'18 -25'，'25及以上'，并使用存储过程返回此结果集。

理想情况下，我需要返回2个字段，'Age Band'，'Total'就像这样

Age band         Total 
12 and under     5
13 - 17          8
18 - 25          7
25 and over      10

Answer 1

创建一个包含您的乐队的表格：

CREATE TABLE agebands
(
    id INT NOT NULL PRIMARY KEY,
    lower_bound INT NOT NULL,
    upper_bound INT NOT NULL
)
CREATE INDEX IDX_agebands_bounds ON (lower_bound, upper_bound)

然后用您的数据填充它：

INSERT INTO agebands VALUES (1, 0, 12)
INSERT INTO agebands VALUES (2, 13, 17)
INSERT INTO agebands VALUES (3, 18, 24)
INSERT INTO agebands VALUES (4, 25, 199)

然后加入它：

SELECT
    lower_bound, upper_bound,
    COUNT(*) AS number_of_people
FROM
    persons
    INNER JOIN agebands
        ON person_age BETWEEN lower_bound AND upper_bound
GROUP BY
    lower_bound, upper_bound
ORDER BY
    lower_bound

这允许灵活地调整频带。 当然，这里使用UNION的另一个答案也是可用的，如果您可以/不会将另一个表添加到数据库中，这更合适。

Answer 2

一个简单的UNION就足够了。

SELECT [Ageband] = '12 and under', COUNT(*)
FROM dbo.Person
WHERE PersonAge <= 12
UNION ALL SELECT '13-17', COUNT(*)
FROM dbo.Person
WHERE PersonAge BETWEEN 13 AND 17
UNION ALL SELECT '18-25', COUNT(*)
FROM dbo.Person
WHERE PersonAge BETWEEN 18 AND 25
UNION ALL SELECT '26 and over', COUNT(*)
FROM dbo.Person
WHERE PersonAge >= 26

Answer 3

以下应该给出：

select count(*), person_age
from (
    select (case 
               when age between 0 and 12 then '12 and under'
               when age between 13 and 17 then '13-17'
               when age between 18 and 25 then '18-15'
               else 'Above 25'
            end) as 'person_age'
    from person)
group by person_age

Answer 4

在SQL中，您不能按列别名进行分组。 您需要像这样重复案例陈述。

select count(*), 
case  
    when aged between 0 and 12 then '12 and under'
    when aged between 13 and 17 then '13-17'
    when aged between 18 and 25 then '18-15'
    else 'Above 25' end
from person
group by 
case  
    when aged between 0 and 12 then '12 and under'
    when aged between 13 and 17 then '13-17'
    when aged between 18 and 25 then '18-15'
    else 'Above 25'
end

Answer 5

declare @tempT table(age int)
declare @temp2 table(age2 varchar(15))

insert into @tempT(age) values(1)
insert into @tempT(age) values(2)
insert into @tempT(age) values(3)
insert into @tempT(age) values(4)
insert into @tempT(age) values(5)
insert into @tempT(age) values(6)
insert into @tempT(age) values(7)
insert into @tempT(age) values(8)
insert into @tempT(age) values(9)
insert into @tempT(age) values(10)
insert into @tempT(age) values(11)

insert into @Temp2
select  case  
when age < 3 then '<3'
when age >= 3 and age < 5 then '>= 3 and < 5'
when age >= 5 then '>=5'
end
from @tempT

select count(*), age2 from @Temp2 
GROUP BY age2