text: from django.db import models
  from patient import models as pmodels
  from donor import models as dmodels
  
  class Stock(models.Model):
      bloodgroup=models.CharField(max_length=10)
      unit=models.PositiveIntegerField(default=0)
      def __str__(self):
          return self.bloodgroup
  
  class BloodRequest(models.Model):
      request_by_patient=models.ForeignKey(pmodels.Patient,null=True,on_delete=models.CASCADE)
      request_by_donor=models.ForeignKey(dmodels.Donor,null=True,on_delete=models.CASCADE)
      patient_name=models.CharField(max_length=30)
      patient_age=models.PositiveIntegerField()
      reason=models.CharField(max_length=500)
      bloodgroup=models.CharField(max_length=10)
      unit=models.PositiveIntegerField(default=0)
      status=models.CharField(max_length=20,default="Pending")
      date=models.DateField(auto_now=True)
      def __str__(self):
          return self.bloodgroup
  
  class Subs(models.Model):
      email = models.EmailField()
          