我搜索了很多例子,我得到了很好的例子:
但没有得到最有希望的解决方案,所以我可以在我的 mysql 函数中使用来查询数以万计的行。
这是一个非常新的概念,但不适用于像@start_date = '2013-08-03' , @end_date = '2013-08-21'
Expected ans : 13 这样的输入,它只给出 12,
SELECT 5 * (DATEDIFF(@end_date, @start_date) DIV 7) + MID('0123444401233334012222340111123400012345001234550', 7 * WEEKDAY(@start_date) + WEEKDAY(@end_date) + 1, 1);
所以我确实试着自己做——
Concept :
Input : 1. period_from_date - from date
2. period_to_date - to date
3. days_to_exclude - mapping : S M T W TH F Sat => 2^0 + 2^6
(sat and sun to exclude) ^ ^ ^ ^ ^ ^ ^
0 1 2 3 4 5 6
DELIMITER $$
USE `db_name`$$
DROP FUNCTION IF EXISTS `FUNC_CALC_TOTAL_WEEKDAYS`$$
CREATE DEFINER=`name`@`%` FUNCTION `FUNC_CALC_TOTAL_WEEKDAYS`( period_from_date DATE, period_to_date DATE, days_to_exclude INT ) RETURNS INT(11)
BEGIN
DECLARE period_total_num_days INT DEFAULT 0;
DECLARE period_total_working_days INT DEFAULT 0;
DECLARE period_extra_days INT DEFAULT 0;
DECLARE period_complete_weeks INT DEFAULT 0;
DECLARE extra_days_start_date DATE DEFAULT '0000-00-00';
DECLARE num_days_to_exclude INT DEFAULT 0;
DECLARE start_counter_frm INT DEFAULT 0;
DECLARE end_counter_to INT DEFAULT 6;
DECLARE temp_var INT DEFAULT 0;
# if no day to exclude return date-diff only
IF days_to_exclude = 0 THEN
RETURN DATEDIFF( period_to_date, period_from_date ) + 1 ;
END IF;
# get total no of days to exclude
WHILE start_counter_frm <= end_counter_to DO
SET temp_var = POW(2,start_counter_frm) ;
IF (temp_var & days_to_exclude) = temp_var THEN
SET num_days_to_exclude = num_days_to_exclude + 1;
END IF;
SET start_counter_frm = start_counter_frm + 1;
END WHILE;
# Get period days count
SET period_total_num_days = DATEDIFF( period_to_date, period_from_date ) + 1 ;
SET period_complete_weeks = FLOOR( period_total_num_days /7 );
SET period_extra_days = period_total_num_days - ( period_complete_weeks * 7 );
SET period_total_working_days = period_complete_weeks * (7 - num_days_to_exclude);
SET extra_days_start_date = DATE_SUB(period_to_date,INTERVAL period_extra_days DAY);
# get total working days from the left days
WHILE period_extra_days > 0 DO
SET temp_var = DAYOFWEEK(period_to_date) -1;
IF POW(2,temp_var) & days_to_exclude != POW(2,temp_var) THEN
SET period_total_working_days = period_total_working_days +1;
END IF;
SET period_to_date = DATE_SUB(period_to_date,INTERVAL 1 DAY);
SET period_extra_days = period_extra_days -1;
END WHILE;
RETURN period_total_working_days;
END$$
DELIMITER ;
请让我知道这会失败的漏洞。欢迎提出任何建议和意见。