Question

I want to integrate an async treeview in PHP. Now i want to know how to generate a source php file with PHP.

Now my database structure is like this:

Create table School(
id int(10) NOT NULL AUTO_INCREMENT, 
name varchar(50), 
primary key(id)
);
Create table Class(
id int(10) NOT NULL AUTO_INCREMENT,
name varchar(50), 
school_id int(10), 
primary key(id), 
foreign key(school_id) reference School(id) on delete cascade
);
Student(
id int(10) NOT NULL AUTO_INCREMENT, 
name varchar(50), 
class_id int(10),
primary key(id), 
foreign key(class_id) reference Class(id) on delete cascade
);



School -> Class -> Student

Now, i want to realize the treeview. Do you have any ideas of implementing it?

Thanks a lot.

Additional question: When i finish the treeview. If i click the items in the treeview, it will generate a result table by clicking. Do you know how to do that?

However, firstly i should finish the treeview.

Answer 1

So basically you need to (pseudo code):

$tree = array();
/**
 * the following line essentially executes the Query:
 * SELECT * from schools;
 * and returns all the rows in an array like 
 * $schools = Array(0=>array('id'=>1, 'name' => 'name'))
 */
$schools = $db->schools()->selectAll();

foreach($schools as $school)
{
   $schoolArr = array('text' => $school['name']);

   /**
    * Similar to the calls to school above except the query would be:
    * SELECT * from class where class.school_id = $school['id']
    * $school['id'] is the pk from the particular school record
    */
   $classes = $db->classes()->select("school_id = ?", $school['id']);
   $classesArr = array();
   foreach($classes as $class)
   {
      $classArr = array('text' => $class['name']);
      /**
       * Similar to the calls to school above except the query would be:
       * SELECT * from student where student.class_id = $class['id']
       * $class['id'] is the pk from the particular class record
       */
      $students = $db->students()->select('class_id = ?', $class['id']);
      $studentsArr = array();
      foreach($students as $student)
      {
          $studentsArr[] = array('text' => $student['name']);
      }

      $classArr['children'] = $studentsArr;
      $classesArr[] = $classArr;
   }

   $schoolArr['children'] = $classesArr;
   $tree[] = $schoolArr;
}

$jsTreeString = json_encode($tree);

Now obviously as you go through each loop you need to be assinging your other tree properties. then when youre all done just json_encode the array and echo it where i needs to be. At least thats how id work it. Note though, that you can probably do this without an individual query using some joins but i didnt want to get into all that – youll definitely wann explore that though if performance is at all an issue.