Stopping loop before counter reaches 0 - php

Question

For now the no of vacancy is 3 for that company. I want it to stop subtracting at 0.
This is my code:
$result4 = mysqli_query($con,"SELECT no_of_vacancy FROM job_details WHERE jobscope= 'Information Technology' AND job_title='Oak 3 Films Pte Ltd (Sales Marketing Department)';");
$result5 = mysqli_query($con, "SELECT COUNT(company) FROM student_details WHERE jobscope1 = 'myJobScope' AND company = 'myCompany';");
while ($row5 = mysqli_fetch_assoc($result5))
{
$result6 = mysqli_query($con, "UPDATE `job_details` SET `no_of_vacancy`= `no_of_vacancy` - 2 WHERE `job_title` = 'myCompany';"));
}
I want to subtract a value from a company's no of vacancy once a student is assigned to it.
Company | Vacancy|
ABC | 3
I want it to show 0 once 3 students is assigned to it. For now it goes till -1 every time the code runs.

Answer 1

To stop loop execution:
while ($row5 = mysqli_fetch_assoc($result5))
{
$result6 = mysqli_query([...]);
if(condition)
break;
}
To skip current execution:
while ($row5 = mysqli_fetch_assoc($result5))
{
if(condition)
continue;
$result6 = mysqli_query([...]);
}

Answer 2

You stop While loop with break;
You can stop everything with exit;
What is the point of this code ?

Answer 3

Did you already try using "break"?
You could for example use your code in the following manner:
$result4 = mysqli_query($con,"SELECT no_of_vacancy FROM job_details WHERE jobscope= 'Information Technology' AND job_title='Oak 3 Films Pte Ltd (Sales Marketing Department)';");
$result5 = mysqli_query($con, "SELECT COUNT(company) FROM student_details WHERE jobscope1 = 'Information Technology' AND company = 'Oak 3 Films Pte Ltd (Sales Marketing Department)';");
while ($row5 = mysqli_fetch_assoc($result5))
{
$result6 = mysqli_query($con, "UPDATE `job_details` SET `no_of_vacancy`= `no_of_vacancy` - 2 WHERE `job_title` = 'Oak 3 Films Pte Ltd (Sales Marketing Department)';"));
if ($result6 == 0)
{
break;
}
I hope it could help.