mysql - 如何从MYSQL中的日期列表中获取开始年份和结束年份

Question

这是我的项目表。它有两个字段 id 和 project_created_date。我想从 project_created_date 获取开始年份和结束年份。在本例中，起始年份为 2016 年，结束年份为 2018 年。

 -----------------------------------
|   ID  |   PROJECT_CREATED_DATE    |
 -----------------------------------
|   1   |       2018-07-11          |
 -----------------------------------
|   2   |       2018-07-13          |
 -----------------------------------
|   3   |       2018-07-23          |
 -----------------------------------
|   4   |       2016-12-14          |
 -----------------------------------
|   5   |       2017-07-31          |
 -----------------------------------

如果我这样查询，我可以获得开始和结束年份。

 SELECT year(PROJECT_CREATED_DATE) as startYear FROM `projects` ORDER BY PROJECT_CREATED_DATE ASC LIMIT 1
 SELECT year(PROJECT_CREATED_DATE) as endYear FROM `projects` ORDER BY PROJECT_CREATED_DATE DESC LIMIT 1

但我想将查询合并为一个。我的意思是我想得到这样的结果

  ------------------------------
|   startYear   |   endYear     |
 -------------------------------
|       2016    |     2018      |
 -------------------------------

Answer 1

只需使用min 和max 函数

      SELECT min(year(PROJECT_CREATED_DATE)) as  startYear,
        max(year(PROJECT_CREATED_DATE)) as EndYear FROM `projects`