Retrieval of data from database using mysql

Question

I need to make a project of making a Professor timetable retrieval system.I plan to create aa html page and make a drop-down menu use some CSS scripting and php; selecting the professor's name and day of the week. This directs to the database where the selected professor's table is stored and then it must show in result that day professor's schedule.

I'm making a 6 tables that would like Monday,Tuesday...Saturday each table having attributes p_id,p_name,period 1,period 2,...,period 8.

My exact question is how to retrieve the specific professor's data on a particular day?

Answer 1

You mention that you will be using PHP. Have you set up your database tables yet?

As a rough guess, you will need at least a professor table and a professor_appointment table. The professor table could have an auto-incrementing id , personal name fields and whatever else you deem relevant.

The professor_appointment will have a professor_id field, which is a foreign key link to the professor table. It will also need start_time and end_time fields, maybe title , description etc.

To retrieve the specific professor's data on a particular day, you would need a query like:

SELECT pa.*
FROM professor_appointment pa
    INNER JOIN professor p ON pa.professor_id = p.id
WHERE p.id = 1
    AND DATE( pa.start_time ) = '2017-07-20'
ORDER BY pa.start_time ASC;

This would retrieve all of the appointments on 20th July 2017 for the professor with id 1 in the professor table.

A couple of things possible worth explaining in this SQL query:

• Aliases are used for the tables, so the p after the professor table is its alias and every reference thereafter to the professor table just uses the alias p .
• DATE( pa.start_time ) The DATE function is just wrapped around the start_time field to effectively remove the time elements of the field (hours, minutes etc) to just leave the date itself for simple comparison.