如何进行选择查询以从一个表中选择数据并将结果提供给另一个选择

Question

I want to make table in HTML. First column should be names of people and next columns should be date of lessons. I would like to make something like school attendance. When someone was in class the cell should be green when I click on it otherwise it should be white. I want to select names of users and names of lessons from database. How shoul I write good select query that can do what i want?

SCHEME OF TABLE USERS: - id (tinyint) - name (varchar) - password (varchar) md5

SCHEME OF TABLE LESSONS: - id (tinyint) - name (date)

I make an example of data that I want to get:

http://jsfiddle.net/k8UgT/207/

HTML:

<table>
    <tr>
        <th>NAME</th>
        <th>25.10.</th>
        <th>26.10.</th>
    </tr>
        <tr>
        <td>Jack</td>
        <td></td>
        <td></td>
    </tr>
    <tr>
        <td>Sam</td>
        <td></td>
        <td></td>
    </tr>
</table>

JQUERY:

$( function() {
  $('td').click( function() {
    $(this).toggleClass('on');
} )
});

Answer 1

You should have a new table, let's say users_lessons_date with the following structure:

• id
• userId (int) - foreign key table_users
• lessonId (int) - foreigg key lessons
• dateOfLesson (datetime)

And your query, if you're using mysql and you want all date where a user was to lesson, will be:

select dateOfLesson, lessons.name as lessonName, table_users.name = userName
from users_lessons_date uld
join table_users u on ( uld.userId = u.id )
join lessons l on (uld.lessonId = l.id)