Codeigniter: query returns values of NULL - php

Question

Hi there I am trying to check if my query is successful but it is returning indexes of NULL values making it seem that the query is successful. How can I check if the query is success in my sample query because I think it shouldn't return NULL indexes.
Model
public function classmanage_classinfo($section_id) {
$query = $this->db->select('students.user_id, students.studentnumber,
students.lastname, students.firstname, students.middlename, students.level, students.year')->from('sections')
->join('student_section', 'student_section.section_id = sections.section_id', 'left')
->join('students', 'students.user_id = student_section.student_id', 'left')
->where('sections.section_id', $section_id)
->get();
if ($query->num_rows() > 0) {
return $query->result();
} else {
return false;
}
}
Controller
$data['class_info'] = $this->staff_model->classmanage_classinfo($section_id);
View
<p><?php var_dump($class_info) ?></p>
According to my var_dump the array is counted as a row even though the indexes are null? Why is this happening. How could I make sure that if the query isn't successful it triggers false in my if statement. If there are ways to improve or solve this logic it would be most welcome. Thanks.
Edit:
Full controller
$data['class_info'] = $this->staff_model->classmanage_classinfo($section_id);//determinant if query is null is in the model
$data['section_info'] = $this->staff_model->classmanage_sectioninfo($section_id);
Full Model
public function classmanage_classinfo($section_id) {
$query = $this->db->select('students.user_id, students.studentnumber,
students.lastname, students.firstname, students.middlename, students.level, students.year')->from('sections')
->join('student_section', 'student_section.section_id = sections.section_id', 'left')
->join('students', 'students.user_id = student_section.student_id', 'left')
->where('sections.section_id', $section_id)
->get();
if ($query->num_rows() > 0) {
return $query->result();
} else {
return false;
}
}
public function classmanage_sectioninfo($section_id) {
//section_name
$query = $this->db->select('section_name')->where('section_id', $section_id)->get('sections');
return $query->row();
}

Answer 1

I assume that your query returns many rows not a single row.
$query = $this->db->select('students.user_id, students.studentnumber,
students.lastname, students.firstname, students.middlename, students.level, students.year')->from('sections')
->join('student_section', 'student_section.section_id = sections.section_id', 'left')
->join('students', 'students.user_id = student_section.student_id', 'left')
->where('sections.section_id', $section_id)
->get()->result();
if (!empty($query)) {
return $query->result();
} else {
return false;
}