请用一段mySQL查询出每个职业类型下最大用户年龄的customer_id及该id对应的年龄、月收入我现在写的是一个职业类型下的：SELECT doccupation_v AS 职业类型 dcustomer_id dage AS 年龄 dmon_salary_v AS 月收入 FROM DATA$ d WHERE doccupation_v =Skilled agricultural

您可以使用GROUP BY子句和MAX函数来获取每个职业类型下的最大年龄，然后将结果与原始表连接以获取相应的customer_id、年龄和月收入。修改后的查询如下：

SELECT d1.occupation_v AS '职业类型', d1.customer_id, d1.age AS '年龄', d1.mon_salary_v AS '月收入' FROM DATA$ d1 JOIN (SELECT occupation_v, MAX(age) AS max_age FROM DATA$ GROUP BY occupation_v) d2 ON d1.occupation_v = d2.occupation_v AND d1.age = d2.max_age ORDER BY d1.occupation_v;

这段查询将返回每个职业类型下年龄最大的customer_id、年龄和月收入。