AttributeError: 'ManyToManyField' object has no attribute 'First_Name' - django

Question

i encountered the following problem when i try to migrate list of models one of which contains a ManyToMany field.
class Item(models.Model):
File "C:\Users\helin\Downloads\Django\E-commerce\Farmers\Farmersapp\models.py", line 60, in Item
sluger = farmer.First_Name
AttributeError: 'ManyToManyField' object has no attribute 'First_Name'
Below are the models i created.any help is appreciated.Thank you
class Farmer(models.Model):
id = models.AutoField(default=1,primary_key=True)
First_Name = models.CharField(max_length=15)
Last_Name = models.CharField(max_length=15)
def __str__(self):
return self.First_Name+" "+self.Last_Name
def get_farmer(self):
return self.farmer.First_Name+" " +self.farmer.Last_Name
class Item(models.Model):
id = models.AutoField(default=1,primary_key=True)
category = models.CharField(choices=CATEGORY_CHOICES, max_length=6)
price = models.FloatField()
description = models.TextField(blank=True)
image = models.ImageField()
farmer = models.ManyToManyField(Farmer, through='ItemAmount',related_name='item')
sluger = farmer.First_Name
slug = models.SlugField(default=sluger)
def __str__(self):
return self.category
class ItemAmount(models.Model):
farmer = models.ForeignKey(Farmer, on_delete=models.CASCADE)
item = models.ForeignKey(Item, on_delete=models.CASCADE)
quantity = models.IntegerField(default=1)

Answer 1

First, would suggest to take a look at Python style guide, like lowercase attribute names, etc.
Django auto-creates id primary-key field on every model, unless other field is set as primary-key. So, this part can be safely avoided.
get_farmer method - how is it different from str? Also, these are model instance methods ((self)), so there is no self.farmer field on Farmer object - this will fail.
class Farmer(models.Model):
# id AutoFied is created by default by django, so no need to specify
# id = models.AutoField(default=1,primary_key=True)
first_name = models.CharField(max_length=15)
last_name = models.CharField(max_length=15)
def __str__(self):
return self.first_name + " " + self.last_name
farmer = models.ManyToManyField() - as it is ManyToMany, this means many farmers, so it is better to name field farmers, also same applies to reverse relation - Farmer might have multiple items - related_name=items.
sluger - is it a field? Also, it might have many farmers, so which one to pick?
slug - referencing self fields in default is not good idea, better set default in forms.
You can make slug CharField and set its value in save() method for example.
class Item(models.Model):
# id AutoFied is created by default by django, so no need to specify
# id = models.AutoField(default=1,primary_key=True)
category = models.CharField(choices=CATEGORY_CHOICES, max_length=6)
price = models.FloatField()
description = models.TextField(blank=True)
image = models.ImageField()
farmers = models.ManyToManyField(
Farmer,
through='ItemAmount',related_name='items'
)
slug = models.SlugField()
def __str__(self):
return self.category
You can start with minimum working models and add new fields / methods one by one - it would be easier to debug and you will have base working app.