i'm trying to post a transaction via django rest framework, however it shows error in django log as below:
IntegrityError at /api/item_trans/
NOT NULL constraint failed: chemstore_itemtransaction.bin_code_id
it has no problem if I post the same data from the Django admin web.
therefore I suppose the problem has happened at DRF
any help is welcome, thank you
models.py
class BinLocation(models.Model):
bin_code = models.CharField(max_length=10, unique=True)
desc = models.CharField(max_length=50)
def __str__(self):
return self.bin_code
class Meta:
indexes = [models.Index(fields=['bin_code'])]
class ItemMaster(models.Model):
item_code = models.CharField(max_length=20, unique=True)
desc = models.CharField(max_length=50)
long_desc = models.CharField(max_length=150, blank=True)
helper_qty = models.DecimalField(max_digits=10, decimal_places=4)
unit = models.CharField(max_length=10, blank=False)
def __str__(self):
return self.item_code
class Meta:
verbose_name = "Item"
verbose_name_plural = "Items"
indexes = [models.Index(fields=['item_code'])]
class ItemTransaction(models.Model):
# trace_code YYMMDDXXXX where XXXX is random generated
trace_code = models.CharField(max_length=20, unique=False)
item_code = models.ForeignKey(
ItemMaster, on_delete=models.CASCADE, related_name='+', blank=False, null=False)
datetime = models.DateTimeField(auto_now=False, auto_now_add=False)
qty = models.DecimalField(max_digits=10, decimal_places=4)
unit = models.CharField(max_length=10, blank=False)
action = models.CharField(
max_length=1, choices=ACTION, blank=False, null=False)
bin_code = models.ForeignKey(
BinLocation, related_name='+', on_delete=models.CASCADE, blank=False, null=False)
remarks = models.TextField(blank=True)
def __str__(self):
return f"{self.trace_code} {self.datetime} {self.item_code} {dict(ACTION)[self.action]} {self.qty} {self.unit} {self.bin_code}"
serializers.py
class ItemMasterSerializer(serializers.ModelSerializer):
class Meta:
model = ItemMaster
fields = '__all__'
class ItemTransactionSerializer(serializers.ModelSerializer):
item_code = serializers.SlugRelatedField(
slug_field='item_code',
read_only=True
)
bin_code = serializers.SlugRelatedField(
slug_field='bin_code',
read_only=True,
allow_null=False
)
class Meta:
model = ItemTransaction
fields = '__all__'
You might need to use 2 fields, one for reading data and the other for creating and updating your data with its source to the main. In your case you could try this:
class ItemTransactionSerializer(serializers.ModelSerializer):
item_code_id = ItemMasterSerializer(read_only=True)
item_code = serializers.PrimaryKeyRelatedField(
queryset=ItemMaster.objects.all(),
write_only=True,
source='item_code_id'
)
bin_code_id = BinLocationSerializer(read_only=True
bin_code = serializers.PrimaryKeyRelatedField(
queryset= BinLocation.objects.all(),
write_only=True,
source='bin_code_id'
)
Since you have null=False in both of your ForeignKeys, DRF expects the corresponding ID. You seem to be getting the error NOT NULL constraint because you are not passing the ID in DRF. So you need to fix that for both bin_code_id and the item_code_id.
Related
I'm getting an error when I try to serialize a many-to-many relationship
The error description that is shown to me in the console is this:
AttributeError: Got AttributeError when attempting to get a value for field produto on serializer Ped_ProSerializer.
The serializer field might be named incorrectly and not match any attribute or key on the Produto instance.
Original exception text was: 'Produto' object has no attribute 'produto'.
The models involved in the relationship are written like this:
class Produto(models.Model):
valor_unitario = models.DecimalField(max_digits=10, decimal_places=2, default=0.00)
nome = models.CharField(max_length=75)
descricao = models.TextField()
genero = models.CharField(max_length=10, default="Indefinido")
qtd_estoque = models.IntegerField()
cor = models.ForeignKey(Cor, on_delete=models.PROTECT, related_name="produtos")
tamanho = models.ForeignKey(
Tamanho, on_delete=models.PROTECT, related_name="produtos"
)
marca = models.ForeignKey(Marca, on_delete=models.PROTECT, related_name="produtos")
class Pedido(models.Model):
endereco_entrega = models.ForeignKey(
Endereco, on_delete=models.PROTECT, null=True, related_name="pedidos"
)
forma_pagamento = models.ForeignKey(
Forma_Pagamento, on_delete=models.PROTECT, null=True, related_name="pedidos"
)
usuario_dono = models.ForeignKey(
get_user_model(), on_delete=models.PROTECT, related_name="pedidos"
)
data_entrega = models.DateField()
data_pedido = models.DateField(default=date.today)
finalizado = models.BooleanField(default=False)
qtd_parcela = models.IntegerField()
valor_parcela = models.DecimalField(max_digits=10, decimal_places=2, default=0.00)
preco_total = models.DecimalField(max_digits=10, decimal_places=2, default=0.00)
itens = models.ManyToManyField(Produto, related_name="pedidos", through="Ped_Pro")
class Ped_Pro(models.Model):
produto = models.ForeignKey(
Produto, on_delete=models.PROTECT, related_name="ped_pros"
)
pedido = models.ForeignKey(
Pedido, on_delete=models.PROTECT, related_name="ped_pros"
)
qtd_produto = models.IntegerField(default=1)
data_entrada = models.DateTimeField(default=datetime.now)
The serializers:
class ProdutoSerializer(ModelSerializer):
class Meta:
model = Produto
fields = "__all__"
class Ped_ProSerializer(ModelSerializer):
class Meta:
model = Ped_Pro
fields = "__all__"
class PedidoSerializer(ModelSerializer):
itens = Ped_ProSerializer(many=True, read_only=True)
class Meta:
model = Pedido
fields = "__all__"
Could you help me find a way to the solution?
Project link on Github
In class ped pro you have 2 times the same related name: ped_pros
I want to be able to do queries involving multiple inner joins using Django ORM, here's my model (showing only relevant fields)
class Students(models.Model):
class Status(models.IntegerChoices):
preRegistered = 0 #No ha aceptado terminos y condiciones
Enabled = 1
Disabled = 2
Suspended = 3
Test = 4
id = models.AutoField(primary_key=True)
user = models.ForeignKey(Users, on_delete=models.CASCADE)
trainingPath = models.ForeignKey(trainingPaths, on_delete=models.CASCADE)
status = models.IntegerField(choices=Status.choices, default=0)
creationDate = models.DateTimeField(auto_now_add=True)
modificationDate = models.DateTimeField(auto_now=True)
class Meta():
db_table = 'Students'
class trainingPaths(models.Model):
id = models.AutoField(primary_key=True)
name = models.CharField(max_length=70, blank=False, null=False)
shortName = models.CharField(max_length=10, blank=True)
creationDate = models.DateTimeField(auto_now_add=True)
modificationDate = models.DateTimeField(auto_now=True)
class Meta():
db_table = 'Training_Path'
class Courses(models.Model):
id = models.AutoField(primary_key=True)
name = models.CharField(max_length=70, blank=False, null=False)
path = models.URLField(max_length=500, blank=True, null=True)
shortName = models.CharField(max_length=6, blank=True)
creationDate = models.DateTimeField(auto_now_add=True)
modificationDate = models.DateTimeField(auto_now=True)
course_image = models.URLField(max_length=200, blank=True)
class Meta():
db_table = 'Courses'
class CoursesXTrainingP(models.Model):
id = models.AutoField(primary_key=True)
trainingPath = models.ForeignKey(trainingPaths, on_delete=models.CASCADE)
course = models.ForeignKey(Courses, on_delete=models.CASCADE)
alternativeName = models.CharField(max_length=70, blank=True)
order = models.PositiveIntegerField(blank=False)
creationDate = models.DateTimeField(auto_now_add=True)
modificationDate = models.DateTimeField(auto_now=True)
class Meta():
db_table = 'Courses_X_Training_Paths'
I want to get the information of the courses that a student has according to the value of the "trainingPath".
this is my SQL query
select
courses.id, courses.`name`, courses.course_image
from
students
join
courses_x_training_paths
on
students.trainingPath_id = courses_x_training_paths.trainingPath_id
join
courses
on
courses_x_training_paths.course_id = courses.id
where
students.trainingPath_id=1;
I have tried several ways and none of them have worked, could you please help me?
You can filter with:
Courses.objects.filter(
coursesxtrainingp__trainingPath_id=1
)
The join on the Students model is not necessary, since we already know that the trainingPath_id is one by filtering on the CoursesXTrainingP model.
Note: normally a Django model is given a singular name, so Student instead of Students.
Note: normally the name of the fields in a Django model are written in snake_case, not PascalCase, so it should be: modification_date instead of modificationDate.
I followed Dennis Ivy proshop Tutorial He used the same approach as the code is
class ReviewSerializer(serializers.ModelSerializer):
class Meta:
model = Review
fields = '__all__'
class ProductSerializer(serializers.ModelSerializer):
reviews = serializers.SerializerMethodField(read_only=True)
class Meta:
model = Product
fields = '__all__'
def get_reviews(self, obj):
reviews = obj.review_set.all()
serializer = ReviewSerializer(reviews, many=True)
return serializer.data
Now I need a Blog for the eCommerce Project and I created another app named blog and Created the models as
class BlogPost(models.Model):
_id = models.AutoField(primary_key=True, editable=False)
user = models.ForeignKey(User, on_delete=models.SET_NULL, null=True)
title = models.CharField(max_length=200, null=True, blank=True, help_text="Like How To Treat Hypertension etc")
image = models.ImageField(null=True, blank=True,
default='/placeholder.png')
rating = models.DecimalField(
max_digits=7, decimal_places=2, null=True, blank=True)
numReviews = models.IntegerField(null=True, blank=True, default=0)
createdAt = models.DateTimeField(auto_now_add=True)
youtubeVideoLink = models.CharField(max_length=1000, null=True , blank=True)
def __str__(self):
return str(self.createdAt)
class BlogPostReview(models.Model):
blogpost = models.ForeignKey(BlogPost, on_delete=models.SET_NULL, null=True)
user = models.ForeignKey(User, on_delete=models.SET_NULL, null=True)
name = models.CharField(max_length=200, null=True, blank=True)
rating = models.IntegerField(null=True, blank=True, default=0)
comment = models.TextField(null=True, blank=True)
createdAt = models.DateTimeField(auto_now_add=True)
_id = models.AutoField(primary_key=True, editable=False)
def __str__(self):
return str(self.rating)
But when I serialize them via same approach as mentioned above....
class BlogPostReviewSerializer(serializers.ModelSerializer):
class Meta:
model = BlogPostReview
fields = '__all__'
class BlogPostSerializer(serializers.ModelSerializer):
blog_post_reviews = serializers.SerializerMethodField(read_only=True)
class Meta:
model = BlogPost
fields = '__all__'
def get_blog_post_reviews(self, obj):
blog_post_reviews = obj.review_set.all()
serializer = BlogPostReviewSerializer(blog_post_reviews, many=True)
return serializer.data
This error comes
in get_blog_post_reviews
blog_post_reviews = obj.review_set.all()
AttributeError: 'BlogPost' object has no attribute 'review_set'
How to solve this problem or what I'm doing wrong and what need to be fixed. What would be another apporach obv there would be.... And I don't know why Dennis Ivy used review_set in his code. If someone know why we use _set and what are the circumstances please let me know.
The simplest solution is to update your get_blog_post_reviews method:
def get_blog_post_reviews(self, obj):
blog_post_reviews = obj.blogpostreview_set.all() # <- this line has changed
serializer = BlogPostReviewSerializer(blog_post_reviews, many=True)
return serializer.data
The original worked because there was a model named Review, so the automatically created reverse name was review_set. Your model is named BlogPostReview, so the reverse is blogpostreview_set.
More information about reverse relationships in the docs.
I need to log the transaction of the item movement in a warehouse. I've 3 tables as shown in the below image. However Django response error:
ERRORS:
chemstore.ItemTransaction: (models.E007) Field 'outbin' has column name 'bin_code_id' that is used by another field.
which is complaining of multiple uses of the same foreign key. Is my table design problem? or is it not allowed under Django? How can I achieve this under Django? thankyou
DB design
[Models]
class BinLocation(models.Model):
bin_code = models.CharField(max_length=10, unique=True)
desc = models.CharField(max_length=50)
def __str__(self):
return f"{self.bin_code}"
class Meta:
indexes = [models.Index(fields=['bin_code'])]
class ItemMaster(models.Model):
item_code = models.CharField(max_length=20, unique=True)
desc = models.CharField(max_length=50)
long_desc = models.CharField(max_length=150, blank=True)
helper_qty = models.DecimalField(max_digits=10, decimal_places=4)
unit = models.CharField(max_length=10, blank=False)
def __str__(self):
return f"{self.item_code}"
class Meta:
verbose_name = "Item"
verbose_name_plural = "Items"
indexes = [models.Index(fields=['item_code'])]
class ItemTransaction(models.Model):
trace_code = models.CharField(max_length=20, unique=False)
item_code = models.ForeignKey(
ItemMaster, related_name='trans', on_delete=models.CASCADE, null=False)
datetime = models.DateTimeField(auto_now=False, auto_now_add=False)
qty = models.DecimalField(max_digits=10, decimal_places=4)
unit = models.CharField(max_length=10, blank=False)
action = models.CharField(
max_length=1, choices=ACTION, blank=False, null=False)
in_bin = models.ForeignKey(
BinLocation, related_name='in_logs', db_column='bin_code_id', on_delete=models.CASCADE, null=False)
out_bin = models.ForeignKey(
BinLocation, related_name='out_logs', db_column='bin_code_id', on_delete=models.CASCADE, null=False)
remarks = models.TextField(blank=True)
def __str__(self):
return f"{self.trace_code} {self.datetime} {self.item_code} {dict(ACTION)[self.action]} {self.qty} {self.unit} {self.in_bin} {self.out_bin}"
you have same db_column in two fields so change it
in_bin = models.ForeignKey(
BinLocation, related_name='in_logs', db_column='bin_code_id', on_delete=models.CASCADE, null=False)
out_bin = models.ForeignKey(
BinLocation, related_name='out_logs', db_column='other_bin_code', on_delete=models.CASCADE, null=False) /*change db_column whatever you want but it should be unique*/
If are linked to the same model name, You should use different related_name for each foreign_key filed . here is the exemple :
address1 = models.ForeignKey(Address, verbose_name=_("Address1"),related_name="Address1", null=True, blank=True,on_delete=models.SET_NULL)
address2 = models.ForeignKey(Address, verbose_name=_("Address2"),related_name="Address2", null=True, blank=True,on_delete=models.SET_NULL)
thank you for everyone helped. According to Aleksei and Tabaane, it is my DB design issue (broken the RDBMS rule) rather than Django issue. I searched online and find something similar: ONE-TO-MANY DB design pattern
In my case, I should store in bin and out bin as separated transaction instead of both in and out in a single transaction. This is my solution. thankyou.
p.s. alternative solution: I keep in bin and out bin as single transaction, but I don't use foreign key for bins, query both in bin and out bin for the bin selection by client application.
I have two models:
class Album(models.Model):
code = models.CharField(max_length=10, primary_key=True, default=_create_access_code, verbose_name=_("Id"))
name = models.CharField(max_length=200, verbose_name=_("Name"))
description = models.TextField(null=True, blank=True, verbose_name=_("Description"))
company = models.ForeignKey(Company, on_delete=models.PROTECT, related_name='albums', verbose_name=_("Company"))
access_code = models.CharField(max_length=10, default=_create_access_code, verbose_name=_("Internal Use"))
class Meta:
verbose_name = _("Album")
verbose_name_plural = _("Albums")
def __str__(self):
return "[{}] {} ({})".format(self.pk, self.name, self.company.id)
class Photo(models.Model):
name = models.CharField(max_length=100, null=True, blank=True, verbose_name=_("Name"))
album = models.ForeignKey(Album, on_delete=models.CASCADE, related_name='photos', verbose_name=_("Album"))
photo = models.ImageField(verbose_name=_("Photo"))
class Meta:
verbose_name = _("Photo")
verbose_name_plural =_("Photos")
def __str__(self):
return "[{}] {}".format(self.pk, self.name)
I am trying to make a post to the ModelViewSet for model Albums, but I get an error indicating that field photos is required. Even the OPTIONS method indicates it es required.
How can I instruct DRF for not considering look up fields as required? Is it some serializer setting?
You can add required=False to fields in the serializer.
photos = PhotoSerializer(many=True, required=False)
Something like this. Can you post you serializers?