MySQL DATEDIFF函数详解：快速计算日期差与工作日天数

DATEDIFF(unit, start_date, end_date)

DATEDIFF(end_date, start_date)

-- MySQL中计算用户年龄 SELECT

user_name,
DATEDIFF(CURDATE(), birth_date) / 365.25 AS approximate_age

FROM users;

-- MySQL中计算工作日天数 SELECT

start_date,
end_date,
(DATEDIFF(end_date, start_date) + 1) 
- (FLOOR((DATEDIFF(end_date, start_date) + WEEKDAY(start_date) + 1) / 7) * 2)
- CASE WHEN WEEKDAY(start_date) = 6 THEN 1 ELSE 0 END
- CASE WHEN WEEKDAY(end_date) = 5 THEN 1 ELSE 0 END AS work_days

FROM project_schedule;