Question

我有product和agegroup表。

我正在id来自agegroup表格的agegroup和来自product表格的WITH CTE_AgeGroup AS ( SELECT p.agegroup, CASE WHEN AgeFromMonths >=0 AND AgeToMonths <= 24 THEN CASE WHEN AgeFromMonths >=0 AND AgeToMonths <= 3 THEN '0-3 Months' WHEN AgeFromMonths >=3 AND AgeToMonths <= 6 THEN '3-6 Months' WHEN AgeFromMonths >=6 AND AgeToMonths <= 9 THEN '6-9 Months' WHEN AgeFromMonths >=9 AND AgeToMonths <= 12 THEN '9-12 Months' WHEN AgeFromMonths >=12 AND AgeToMonths <= 18 THEN '12-18 Months' WHEN AgeFromMonths >=18 AND AgeToMonths <= 24 THEN '18-24 Months' END END as 'age' FROM agegroup a inner join product p on a.id= p.agegroup ), CTE_AgeGroupResultSet AS ( select Age, Count(*) AS CountAge from CTE_AgeGroup group by Age ) select * from CTE_AgeGroupResultSet order by age;的比赛中加入这两个表格。

我正在使用的查询在这里;

{{1}}

但是，我的问题是，如果产品A在'0-3个月'中列出，而产品B在'3-6个月'中列出，则这两个产品不会在'0-24个月'中列出。

我想修改我的查询，以便产品A和B也在'0-24个月'中列出

Answer 1

您可以在分组依据中使用with rollup来获取大数：

WITH CTE_AgeGroup AS
(
    SELECT p.agegroup,
           CASE WHEN AgeFromMonths >=0 AND AgeToMonths <= 24 
                THEN CASE WHEN AgeFromMonths >=0 AND AgeToMonths <= 3 
                          THEN '0-3 Months'
                          WHEN AgeFromMonths >=3 AND AgeToMonths <= 6 
                          THEN '3-6 Months'
                          WHEN AgeFromMonths >=6 AND AgeToMonths <= 9 
                          THEN '6-9 Months'
                          WHEN AgeFromMonths >=9 AND AgeToMonths <= 12 
                          THEN '9-12 Months'
                          WHEN AgeFromMonths >=12 AND AgeToMonths <= 18 
                          THEN '12-18 Months'
                          WHEN AgeFromMonths >=18 AND AgeToMonths <= 24 
                          THEN '18-24 Months'
                      END  
            END as 'age'
    FROM agegroup a 
         inner join product p 
            on a.id= p.agegroup
),
CTE_AgeGroupResultSet AS
(
    select case when grouping (Age) = 1 then '0-24' else Age end Age, 
           Count(*) AS CountAge 
      from CTE_AgeGroup
     group by Age WITH ROLLUP
)
select * 
  from CTE_AgeGroupResultSet 
 order by age;

此外，如果您将varchar列添加到包含组描述的agegroup，您将完全消除案例。

Answer 2

我不确定你为什么要选择这种情况。最好使用 UNION运算符（这只是产品和年龄组表的联合）

FULL OUTER JOIN（连接两个表并从两个表中获取数据，即使两个表中都有NULL值。）

条件超过时的SQL情况

2 个答案: