date time compare in mysql and php for booking meeting

Question

i need to book meeting room start date and end date are of date+time type in mysql when ever user enters data, values get stored in these format 2013-10-03 14:30:00 to 2013-10-03 16:30:00 (both start and end date) and along with that room number(example:2) is also stored.

now suppose user has made a new entry again, with

1)same time and and same booking room ( start_date : 2013-10-03 14:30:00 to end_date: 2013-10-03 16:30:00)
2)different time and same booking room (start_date:2013-10-03 13:30:00 to end_date: 2013-10-03 15:30:00)
3)different time and same booking room (start_date:2013-10-03 15:30:00 to end_date: 2013-10-03 18:30:00)

in all above case, it should so me error saying this time is not available as its already booked.

what i have done till now is :

SELECT  * FROM    calendar WHERE `Room_no`='2' and (StartTime BETWEEN $start_date AND '$start_date' OR EndTime BETWEEN $start_date AND $end_date)

Thanks in advance.i am new to php and mysql.so if any mistake i have done please let me know.

Answer 1

At first it's very difficult to know what your exact problem is.

Look at the query below. You are using between query between same variable names $start_date and '$start_date'.

SELECT * FROM calendar WHERE Room_no ='2'
AND (StartTime BETWEEN ) OR (EndTime BETWEEN $start_date AND $end_date) ）或（结束时间在$ start_date和$ end_date之间）

I think you have wrong sql.