Question

我不太确定如何将它标题为一个非常奇怪的问题。我正在构建一个稍微高级的查询，除了它返回该ID下的所有信息

之外它一切正常

以下是我的代码：

select surname, salary_per_year, position _held, grade, name 
from person inner join career_history on person.person_id = career_history.person_id
join grade on grade.person_id = career_history.person_id
join school on grade.school_id = school.school_id
where salary_per_year > 20000 and grade >65;

这会创建此表。

+----------+-----------------+--------------------+-------+---------------------------+
| surname  | salary_per_year | position_held      | grade | name                      |
+----------+-----------------+--------------------+-------+---------------------------+
| webster  |           32000 | data analyst       |    78 | Oxford University         |
| webster  |           23000 | data analyst       |    78 | Oxford University         |
| molina   |           21000 | receptionist       |    81 | UNAM                      |
| jones    |           22000 | law assistant      |    69 | University of Queensland  |
| jones    |           39000 | junior lawyer      |    69 | University of Queensland  |
| lovely   |           26000 | junior analyst     |    71 | Univesity of Bristol      |
| clark    |           23000 | junior banker      |    68 | Harvard Univeristy        |
| clark    |           65000 | head banker        |    68 | Harvard Univeristy        |
| roberts  |           26000 | researcher         |    69 | MIT                       |
| roberts  |           32000 | teacher            |    69 | MIT                       |
| knght    |           28000 | head of department |    92 | University of Barcelona   |
| knght    |           39000 | campus director    |    92 | University of Barcelona   |
| yanagowa |           39000 | database manager   |    86 | Oxford Brookes Univeristy |
| yanagowa |           55000 | head of data       |    86 | Oxford Brookes Univeristy |
+----------+-----------------+--------------------+-------+---------------------------+

我的问题是如何让它只显示每个姓氏的最高工资。 e.g

yanagowa 55000数据主管86牛津布鲁克斯大学不是Yanagowa 39000数据库maanger 86牛顿布鲁克斯大学

请有人指出我是正确的直接！

Answer 1

试一试。

SELECT surname, max(salary_per_year) as maxSalary, position_held, grade, name 
FROM person
INNER JOIN career_history on person.person_id = career_history.person_id
JOIN grade on grade.person_id = career_history.person_id
JOIN school on grade.school_id = school.school_id
WHERE salary_per_year > 20000 and grade > 65
GROUP BY surname
ORDER BY Max(salary_per_year) DESC;

编辑

ORDER BY实际上可以缩短，我在发布后就指出了这一点。

ORDER BY maxSalary DESC;

Answer 2

使用group by

注意：所有选定的字段必须具有组功能（例如，max，min，sum，avg），如果你正在填写它们

Select surname, max(salary_per_year) from @yourtable
group by surname

MYSQL - 仅返回ID的最大结果

2 个答案:

使用group by