Employee matching query does not exist - django

Question

When im deleting from customer table and employee table im getting this error:
DoesNotExist at /delete/2 Customer matching query does not exist.
Below is the view function code to that wrote to delete the row in each table.
Please, can any one help me to get out from this, any help would be greatly appreciated.
def delete(request, user_id):
delCust = Customer.objects.get(user_id = user_id)
delEmp = Employee.objects.get(user_id = user_id)
delEmp.delete()
delCust.delete()
return redirect("/admins")
Employee table html code:
<table class="table table-responsive d-md-table mb-0">
<thead>
<tr>
<th scope="col" class="border-bottom-0">Job Id</th>
<th scope="col" class="border-bottom-0">Designation</th>
<th scope="col" class="border-bottom-0">Experience</th>
<th scope="col" class="border-bottom-0">Action</th>
</tr>
</thead>
<tbody>
{% for items in Customer %}
<tr>
<td nowrap="">{{items.user_id}}</td>
<td nowrap="">{{items.designation}}</td>
<td nowrap="" class="text-capitalize">{{items.experience}} years</td>
<td nowrap="" class="d-flex">
<button type="submit" class="btn btn-success mr-2 text-capitalize"
data-toggle="modal" data-target="#exampleModal">
Send request
</button>
<!--send request-->
<button type="button" class="btn btn-outline-info mr-2 text-capitalize"
data-toggle="modal" data-target="#studentdetailsmodal">
view
</button>
</td>
</tr>
{% endfor %}
</tbody>
</table>
Here is my model for Customer and employee:
class User(AbstractUser):
is_customer = models.BooleanField(default=False)
is_employee = models.BooleanField(default=False)
first_name = models.CharField(max_length=100)
last_name = models.CharField(max_length=100)
class Customer(models.Model):
user = models.OneToOneField(User, on_delete = models.CASCADE, primary_key = True)
phone_number = models.CharField(max_length=20)
location = models.CharField(max_length=20)
email = models.EmailField(max_length=20)
designation = models.CharField(max_length=20)
experience = models.IntegerField(null=True)
salon_name = models.CharField(max_length=20)
salon_category = models.CharField(max_length=20)
class Employee(models.Model):
user = models.OneToOneField(User, on_delete = models.CASCADE, primary_key = True)
phone_number = models.CharField(max_length=20)
designation = models.CharField(max_length=20)
email = models.EmailField(max_length=20)
current_salary = models.IntegerField()
expected_salary = models.IntegerField()
work_experience = models.CharField(max_length=20)
salon_category = models.CharField(max_length=20)