Data Duplication PHP and Laravel - php

Question

below is my code that duplicates database entries, what could the problem be?
When I try to trigger the end point that fetches employees it duplicates the entries multiple times
$all_employees = Employee::with([
'department',
'sub_department',
'first_supervisor',
'second_supervisor',
'reportingTo',
])
->select(
'employees.*',
'attendance_times.start_time as attendance_time',
'cities.city',
'countries.country',
'pay_frequencies.frequency as pay_frequency',
'duty_types.name as duty_type',
'rate_types.name as rate_type',
'positions.name as position_name',
'departments.department as sub_department',
'supervisors.name as supervisor_name'
)
->leftJoin('positions', function ($join) {
return $join->on('employees.position_id', '=', 'positions.id');
})
->leftJoin('countries', function ($join) {
return $join->on('employees.country_id', '=', 'countries.id');
})
->leftJoin('supervisors', function ($join) {
return $join->on('employees.first_supervisor_id', '=', 'supervisors.id');
})
->leftJoin('cities', function ($join) {
return $join->on('employees.city_id', '=', 'cities.id');
})
->leftJoin('attendance_times', function ($join) {
return $join->on('employees.attendance_time_id', '=', 'attendance_times.id');
})
->leftJoin('departments', function ($join) {
return $join->on('employees.sub_department_id', '=', 'departments.id');
})
->leftJoin('pay_frequencies', function ($join) {
return $join->on('employees.pay_frequency_id', '=', 'pay_frequencies.id');
})
->leftJoin('duty_types', function ($join) {
return $join->on('employees.duty_type_id', '=', 'duty_types.id');
})
->leftJoin('rate_types', function ($join) {
return $join->on('employees.rate_type', '=', 'rate_types.id');
})
->orderBy('employees.id', 'DESC')
->get();
return $this->customSuccessResponseWithPayload($all_employees);

Answer 1

Use with('Relation') while getting One to Many relation's data, because if you use leftJoin, you will get all the relation's data again.
Example:
Every Employee has many attendance_times, so if you create an SQL Query which gets all Employees and joined the attendance_times, the returned data will contain a duplicated EMP data every time it has attendance_times.
Basically use ->with('Relation').

Answer 2

Try to use the distinct with the query to fetch non-repetitive data.
DB::table('table')
->select('job_id')
->distinct()
->get();

Answer 3

It can be solved by adding the groupBy(employees.id) at the end of the query that's how I solved it.