SQL实现工作日计算(2)

                    END WHILE;  

                    SET minutes=minutes+TIMESTAMPDIFF(MINUTE,next_day,end_day);  

                    IF ((DAYOFWEEK(start_day)=7) OR (DAYOFWEEK(start_day)=1)) THEN 

                            SET minutes=minutes+TIMESTAMPDIFF(MINUTE,start_day,CONVERT(CONCAT(SUBSTRING(start_day FROM 1 FOR 10),' 17:30:00'),DATETIME));  

                    END IF;  

            END IF;  

            RETURN minutes;  

END; 

CREATE FUNCTION Time_Span_of_minutes(

start_day DATETIME,

end_day DATETIME)

RETURNS FLOAT

BEGIN

                     -- 返回按分钟计算两段时间的间隔，采用逐日靠近的方法求解，一天按8小时480分钟计算，周末不计，不考虑法定节假日。

                     -- 如果起始日期在周末，则计算当天时间。

                     DECLARE minutes FLOAT;

                     DECLARE next_day DATETIME;

                     SET minutes=0.0;

                     SET next_day=start_day;

                     IF(TIMESTAMPDIFF(DAY,start_day,end_day)<1.0) THEN

                                   SET minutes=minutes+TIMESTAMPDIFF(MINUTE,start_day,end_day);

                     ELSE