laravel - Eloquent ORM resulting MySQL select not returning all rows -

i using laravel's eloquent orm query database infomation, reason resulting query isn't returning of rows.

eloquent query:

\permit::selectraw('concat(lk_departments.dept_id, ".") dept_id, '.                     'lk_departments.dept_name, '.                    'count(distinct permits.permit_number) total')        ->leftjoin('lk_departments', 'permits.dept_id', '=', 'lk_departments.dept_id')        ->where('permits.permit_number', '!=', 'n/a')        ->wherebetween('permits.valid_date', [$query_info['start_date'], $query_info['end_date']])        ->groupby('lk_departments.dept_name')        ->orderby('lk_departments.dept_name', 'asc')        ->get() 

resulting query:

select  concat(lk_departments.dept_id, ".") dept_id, lk_departments.dept_name, count(distinct permits.permit_number) total permits left join lk_departments on permits.dept_id = lk_departments.dept_id permits.valid_date between '01/01/2000' , '12/12/2100' group lk_departments.dept_name order lk_departments.dept_name asc 

returned data:

dept_id             dept_name                       total +--------------------------------------------------------+ | null   null                                       0    |  | 1.     academic achievement-(special services)    11   |  | 3.     academic clubs                             1    |  | 4.     academic custodial & grounds services      1    |  | 5.     accounting                                 2    |  | 6.     admissions                                 356  |  | 7.     advanced programs dept (education dept)    8    |  | 9.     aerospace studies - air force rotc         1    |  | 11.    american federation of teachers            0    |  | 13.    anthropology                               1    |  | 14.    art dept.                                  4    |  | 17.    athletic dept.                             11   |  | 21.    biology dept.                              2    |  |                                                        | | ...    ...                                        ...  | +--------------------------------------------------------+  

referenced question modify total: count distinct values

but still receive 1 null row total of 0 , missing records. i'm not mysql, forgive me if missing something. ideally, count of permits each department given time frame.

note:
dept_id = auto incremented primary key
permits = table containing parking permit information linked department

i figured out problem. when using permits master table in join, neglected realize records dept_id wouldn't show if there no corresponding records permits.dept_id matched lk_departments.dept_id (if nobody had registered permit department, in other words). also, reason, had change query include records permits.permit_number null.

resulting eloquent query:

lkdepartment::selectraw('lk_departments.*, count(permits.permit_number) total')             ->leftjoin('permits', 'lk_departments.dept_id', '=', 'permits.dept_id')             ->wherenull('permits.permit_number')             ->orwhereraw("(permits.permit_number != 'n/a' , permits.valid_date between '$query_info[start_date]' , '$query_info[end_date]')")             ->groupby('lk_departments.dept_id')             ->orderby('lk_departments.dept_id', 'asc')             ->get() 

resulting query:

select lk_departments.* , count( permits.permit_number ) total lk_departments left join permits on lk_departments.dept_id = permits.dept_id permits.permit_number null or (     permits.permit_number != 'n/a'      , permits.valid_date between '01/01/2000' , '12/12/2100' ) group lk_departments.dept_id order lk_departments.dept_id asc  

returned data:

dept_id             dept_name                       total +--------------------------------------------------------+ | null   null                                       0    |  | 1      academic achievement-(special services)    11   |  | 2      academic advising center                   0    |  | 3      academic clubs                             1    |  | 4      academic custodial & grounds services      1    |  | 5      accounting                                 2    |  | 6      admissions                                 356  |  | 7      advanced programs dept (education dept)    8    |  | 8      advisory council                           0    |  | 9      aerospace studies - air force rotc         1    |  | 10     alternative school                         0    |  | 11     american federation of teachers            0    |  | 12     anthropology                               0    |  |                                                        | | ...    ...                                        ...  | +--------------------------------------------------------+