$this->parent_relations[]               = array('parent' => 'candidate',
                                                    'parent_field' => 'concat(first_name, \' \', last_name) as person_name, age_group_id, dob_date, first_name, last_name, gender, candidate_pin, student_ind, addr_line_1, addr_line_2, addr_line_3, town, county, postcode, email_addr, home_telephone, mobile_telephone',
                                                    'fields' => array('candidate_id' => 'candidate_id',
                                                                      'rdcaccount_id' => 'rdcaccount_id'));

SELECT SQL_CALC_FOUND_ROWS exam.*, branch.branch_id, branch.branch_desc, branch.branch_abbrev, branch.syllabus_type_id, branch.student_branch_abbrev, branch.crf_type_id, branch.session_type_id as branch_session_type_id, 
  concat(candidate.first_name,' ',candidate.last_name) AS person_name,
  d1.dance_code AS dance1_code, d2.dance_code AS dance2_code, d3.dance_code AS dance3_code, d4.dance_code AS dance4_code,
  grade.grade_code, grade.grade_desc, school.school_name, school.principal_name, school.principal_mem_num, school.school_addr_line_1, school.school_addr_line_2, school.school_addr_line_3, school.school_town, school.school_county, school.school_postcode, school.school_email_addr, school.school_web_addr, school.school_telephone,
  session.session_desc, session.session_date, session.examiner, session.session_type_id, amount  
FROM exam  
LEFT JOIN branch ON (branch.branch_id=exam.branch_id)  
LEFT JOIN candidate ON (candidate.candidate_id=exam.candidate_id AND candidate.rdcaccount_id=exam.rdcaccount_id)  
LEFT JOIN dance AS d1 ON (d1.dance_id=exam.dance1_id)  
LEFT JOIN dance AS d2 ON (d2.dance_id=exam.dance2_id)  
LEFT JOIN dance AS d3 ON (d3.dance_id=exam.dance3_id)  
LEFT JOIN dance AS d4 ON (d4.dance_id=exam.dance4_id)  
LEFT JOIN grade ON (grade.grade_id=exam.grade_id)  
LEFT JOIN school ON (school.school_id=exam.rdcaccount_id)  
LEFT JOIN session ON (session.rdcaccount_id=exam.rdcaccount_id AND session.session_id=exam.session_id)  
LEFT JOIN cost_group_charge ON (grade.cost_group_id=cost_group_charge.cost_group_id AND session.session_date >= cost_group_charge.start_date AND session.session_date <= cost_group_charge.end_date AND exam.rdcaccount_id = cost_group_charge.rdcaccount_id AND exam.banner_req = cost_group_charge.banner_req AND cost_group_charge.age_group_id IN  (SELECT candidate.age_group_id from candidate where exam.candidate_id = candidate.candidate_id UNION SELECT age_group.age_group_id from age_group where age_group_id = 'X'))   
WHERE exam.rdcaccount_id='7' AND exam.session_id='1'    
ORDER BY exam.exam_seq_nbr asc  
LIMIT 10 OFFSET 0 =>Count=8