How to increment database field values by 1 in Laravel - laravel-4

Question

I have a table student attendance.
Fields/data sample
id | studid | cls_id | smonth | syear | total_p | total_a
1 | 20 | 2 | 08 | 2015 | 2 | 1
2 | 21 | 2 | 08 | 2015 | 1 | 0
3 | 22 | 2 | 08 | 2015 | 2 | 1
I want, to check what is the total_p and total_a value of each students in last update and then increment 1.
If I am enter the both students are present = 1 so I want total_p value 20=3, 21=2, 22=3
How to get database field values and increment 1's.?
My controller
$present = Input::get($student->id);
if ($checkatt)
{
if ($present == 1)
{
DB::table($wys_total_attend_table)->where('studid', $student->id)
->where('smonth', $date_exploded[1])
->where('syear', $date_exploded[2])
->where('stotal_p', 1)
->update(array(
'stotal_p' => 1 + 1,
));
DB::table($wys_total_attend_table)->where('studid', $student->id)
->where('smonth', $date_exploded[1])
->where('syear', $date_exploded[2])
->where('stotal_p', 0)
->update(array(
'stotal_p' => 1,
'stotal_a' => 0,
));
} elseif ($present == 0)
{
DB::table($wys_total_attend_table)->where('studid', $student->id)
->where('smonth', $date_exploded[1])
->where('syear', $date_exploded[2])
->where('stotal_a', 1)
->update(array(
'stotal_a' => 1 + 1,
));
DB::table($wys_total_attend_table)->where('studid', $student->id)
->where('smonth', $date_exploded[1])
->where('syear', $date_exploded[2])
->where('stotal_a', 0)
->update(array(
'stotal_a' => 1,
));
DB::table($wys_total_attend_table)->where('studid', $student->id)
->where('smonth', $date_exploded[1])
->where('syear', $date_exploded[2])
->where('stotal_p', 1)
->where('stotal_a', 0)
->update(array(
'stotal_a' => 0 + 1,
));
}
}

Answer 1

I think u just want to update each record of total_p and total_a column just make it simple:
//get the id of student
$student_id = Input::get('student_id');
$present = Input::get('status'); //dropdown value 0,1
//You need a model for your table let say:
#Student.php
<?php
class Student extends Eloquent{
protected $table = 'students'; //table name
}
//Your Controller codes
public function findStudent($id, $status){
$query=Student::find($id);
if($query->count() && $status==1 ){ //status 1 = present
$query->total_p += 1; //plus one value in the total_p column in the tbl.
$query->save();
}else{
$query->total_a +=1;
$query->save();
}
}