用Java计算年龄组

Question

我有一个age和name customers的SQL表格，想要计算以下年龄段内的客户数量

18-30 31-45 46-60 61 and above

任何想法我该怎么做？

Answer 1

您可以在数据库中执行此操作

WITH C AS(
    SELECT  name
            ,age
            ,CASE
                WHEN age >= 18 AND age <= 30 THEN '18-30'
                WHEN age >= 31 AND age <= 45 THEN '31-45'
                WHEN age >= 46 AND age <= 60 THEN '46-60'
                WHEN age >= 61 THEN '>61'
                ELSE NULL
            END AS AgeGroup
    FROM table
)
SELECT COUNT(AgeGroup) cnt, AgeGroup FROM C GROUP BY AgeGroup