首先,MySQL 包含一个时间数据类型。我强烈建议您利用它。
无论如何,对于您的表格(这是用于学术安排,但适用相同的基本思想):
DaysOfWeek
----------
DowID int
DayOfWeek varchar(10)
Users
------------------------
UserID int autoincrement
UserName varchar(50)
PassHash varbinary(100)
FirstName varchar(50)
LastName varchar(50)
DOB datetime
Semesters
----------------------------
SemesterID int autoincrement
SemesterName varchar(50)
SemesterNumber int
AcademicYear int
CalendarYear int
Classes
-------------------------
ClassID int autoincrement
ClassName varchar(50)
ClassCode varchar(25)
Schedule
----------------------------
ScheduleID int autoincrement
UserID int
SemesterID int
DowID int
ClassID int
BeginTime time
EndTime time
现在,您需要做的就是查看是否有人在周一 1 点到 2 点之间有空:
select
count(*) as classes
from
schedule sch
inner join users u on
sch.userid = u.userid
inner join semesters sem on
sch.semesterid = sem.semesterid
where
u.username = 'rmcdonald'
and sem.academicyear = 2009
and sem.semesternumber = 1
and sch.dowid = dayofweek($mytime)
and $mytime between sch.begintime and sch.endtime
$mytime
用你在那里检查的任何时间替换。