PHP/MYSQL group by column with 2 joined tables

Question

i have a table named "class" with field "section", the section field is joined in "section" table and "course" table. Now i want to display all distinct "section" and group it with "course":

Course 1  
    -Section 1  
    -section 2  

Course 2  
    -section 3  
    -section 4  

here is my query code

return $this->_db->select("
                    SELECT DISTINCT
                        class.section,
                        section.id,
                        section.code,
                        section.name AS sectionname,
                        section.`year`,
                        section.minenrollee,
                        course.code,
                        course.name AS coursename
                    FROM
                        class
                        Inner Join section ON class.section = section.id
                        Inner Join course ON section.course = course.id
                    WHERE
                        class.period =  '".$period."'
                    GROUP BY
                        section.course
                    ORDER BY
                        section.`year` ASC,
                        section.code ASC
                    ");

this is my php code. can anyone help me. thanks in advance

//GET DISTINCT SECTION IN CLASS
        $sections = $this->model->getDistinctsections(Session::get('period'));
        $list = array();
        foreach ($sections as $r) {
            $list[$r->coursename][$r->id]['coursename'] = $r->coursename;
        }
        print_r($list);

Answer 1

Your data should be returning properly as is. That being said, a statement like print_r() will never return the data grouped into a nice, "grouped" list. That's not its job; you'll have to do that on your own.

To get a result you want, you'll need to loop through your data. If a column you're grouping on is the same as the column from the previous row, then you don't need to write it to the table again. Since this isn't a coding service, I'll give you an example data set, and you can work from there.

Example Data:

Company | Department | Employee
-------------------------------
A       | Accounting | John
A       | Accounting | Bill
A       | Billing    | Jane
A       | Billing    | Debra

To print this data into a table, grouping on Company and Department, we need to loop through the data.

Rough algorithm:

1. If the previous Company is null or doesn't match the current row's value, then print the Company value.
2. If the previous Department is null or doesn't match the current row's value, then print the Department value.
3. Print the value of Employee
4. If this isn't the last record, go to step 1.

Following this algorithm should pretty easily get you to a display like

Company | Department | Employee
-------------------------------
A       | Accounting | John
        |            | Bill
        | Billing    | Jane
        |            | Debra

Minor adaptations from you can make it prettier. :)