使用 CONCAT 格式化 MySQL

Question

感谢一些帮助，我有一个 MySQL 查询，该查询从 2014 年 10 月 10 日开始，并对 12 个月内的假期数量进行罚款，例如 2014 年 10 月 10 日到 2015 年 10 月 9 日，然后是 2015 年 10 月 10 日到 2016 年-10-09

SELECT 
    e.name AS Employee,
    CEIL(DATEDIFF(h.date, e.startdate)/365) as Year,
    count(h.date) as Holidays_Taken
FROM employees AS e
LEFT JOIN holidays_taken AS h ON e.id = h.empid
WHERE e.id = 1
GROUP BY Year

结果

+----------+------+---------------+
| Employee | Year | Holidays_Taken|
+----------+------+---------------+
| Jon      | 1    | 5             |
+----------+------+---------------+
| Jon      | 2    | 1             |
+----------+------+---------------+

是否可以让年份显示 2014-10-10 到 2015-10-09 而不是第 1 年，然后在第 2 年显示 2015-10-10 到 2016-10-09

这是我的SQL FIDDLE

谢谢

Answer 1

我会以这种方式创建CONCAT：

SELECT 
    e.name AS Employee,
    CONCAT(
        CEIL(DATEDIFF(h.date, e.startdate)/365), 
        ' (',
        DATE_ADD(e.startdate, INTERVAL FLOOR(DATEDIFF(h.date, e.startdate)/365) YEAR), ' to ',        
        DATE_ADD(e.startdate, INTERVAL CEIL(DATEDIFF(h.date, e.startdate)/365) YEAR),
        ')'
        ) as Year,
    COUNT(h.date) AS Holidays_Taken,
    SUM(h.hours) AS Hours
FROM employees AS e
LEFT JOIN holidays_taken AS h ON e.id = h.empid
WHERE e.id = 1
GROUP BY Year

演示：SQL FIDDLE

Answer 2

不确定我是否达到了您的目标，但这是我的方法：

http://sqlfiddle.com/#!9/371a7/14

SELECT 
    e.name AS Employee,
    @year := CEIL(DATEDIFF(h.date, e.startdate)/365) AS Year,
    CONCAT(DATE_ADD(e.startdate, INTERVAL @year-1 YEAR),' - ',DATE_ADD(e.startdate, INTERVAL @year YEAR)),
    COUNT(h.date) AS Holidays_Taken,
    SUM(h.hours) AS Hours
FROM employees AS e
LEFT JOIN holidays_taken AS h ON e.id = h.empid
WHERE e.id = 1 
GROUP BY Year