Python Error : (fields.E304) Reverse accessor for field clashes with reverse accessor for another field

Question

Below is my models.py file in a Django project. Whenever I try to run the project I get the following error. Please assist as I have just started picking up django I tried changing the names of the foreign columns as suggested by the error but no avail. A lot of answers out there suggest changes with respect to related_name which does not exist in my case.

Error from console

app_fin.TblLockerCoutCin.jewel_item: (fields.E304) Reverse accessor for 'TblLockerCoutCin.jewel_item' clashes with reverse accessor for 'TblLockerCoutCin.jewel_item_code'. HINT: Add or change a related_name argument to the definition for 'TblLockerCoutCin.jewel_item' or 'TblLockerCoutCin.jewel_item_code'. app_fin.TblLockerCoutCin.jewel_item: (fields.E304) Reverse accessor for 'TblLockerCoutCin.jewel_item' clashes with reverse accessor for 'TblLockerCoutCin.jewel_item_name'. HINT: Add or change a related_name argument to the definition for 'TblLockerCoutCin.jewel_item' or 'TblLockerCoutCin.jewel_item_name'. app_fin.TblLockerCoutCin.jewel_item_code: (fields.E304) Reverse accessor for 'TblLockerCoutCin.jewel_item_code' clashes with reverse accessor for 'TblLockerCoutCin.jewel_item'. HINT: Add or change a related_name argument to the definition for 'TblLockerCoutCin.jewel_item_code' or 'TblLockerCoutCin.jewel_item'. app_fin.TblLockerCoutCin.jewel_item_code: (fields.E304) Reverse accessor for 'TblLockerCoutCin.jewel_item_code' clashes with reverse accessor for 'TblLockerCoutCin.jewel_item_name'. HINT: Add or change a related_name argument to the definition for 'TblLockerCoutCin.jewel_item_code' or 'TblLockerCoutCin.jewel_item_name'. app_fin.TblLockerCoutCin.jewel_item_name: (fields.E304) Reverse accessor for 'TblLockerCoutCin.jewel_item_name' clashes with reverse accessor for 'TblLockerCoutCin.jewel_item'. HINT: Add or change a related_name argument to the definition for 'TblLockerCoutCin.jewel_item_name' or 'TblLockerCoutCin.jewel_item'. app_fin.TblLockerCoutCin.jewel_item_name: (fields.E304) Reverse accessor for 'TblLockerCoutCin.jewel_item_name' clashes with reverse accessor for 'TblLockerCoutCin.jewel_item_code'. HINT: Add or change a related_name argument to the definition for 'TblLockerCoutCin.jewel_item_name' or 'TblLockerCoutCin.jewel_item_code'.

models.py

from django.db import models


class TblJewelleryInventory(models.Model):
    id = models.IntegerField(primary_key=True)
    item_code = models.CharField(unique=True, max_length=5, blank=True, null=True)
    item_name = models.CharField(max_length=250, blank=True, null=True)
    base_locker_location = models.CharField(max_length=45, blank=True, null=True)
    updated_at = models.DateTimeField()
    created_at = models.DateTimeField()

    def __str__(self):
        return self.name

    class Meta:
        managed = False
        db_table = 'tbl_jewellery_inventory'


class TblJewelleryInventoryLogs(models.Model):
    id = models.IntegerField(primary_key=True)
    item_id = models.IntegerField()
    item_code = models.CharField(unique=True, max_length=5, blank=True, null=True)
    item_name = models.CharField(max_length=250, blank=True, null=True)
    base_locker_location = models.CharField(max_length=45, blank=True, null=True)
    updated_at = models.DateTimeField()
    created_at = models.DateTimeField()
    triggered_at = models.DateTimeField()

    def __str__(self):
        return self.name

    class Meta:
        managed = False
        db_table = 'tbl_jewellery_inventory_logs'


class TblLockerCoutCin(models.Model):
    jewel_item = models.ForeignKey(TblJewelleryInventory, models.DO_NOTHING)
    jewel_item_code = models.ForeignKey(TblJewelleryInventory, models.DO_NOTHING, db_column='jewel_item_code')
    jewel_item_name = models.ForeignKey(TblJewelleryInventory, models.DO_NOTHING, db_column='jewel_item_name')
    reason = models.CharField(max_length=500, blank=True, null=True)
    is_check_out = models.IntegerField(blank=True, null=True)
    is_check_in = models.IntegerField(blank=True, null=True)
    created_at = models.DateTimeField(blank=True, null=True)

    def __str__(self):
        return self.name
    class Meta:
        managed = False
        db_table = 'tbl_locker_cout_cin'

heemayl heemayl · Accepted Answer · 2019-11-10T12:16:05

In your TblLockerCoutCin model, both jewel_item_code and jewel_item_name fields have a many-to-one relationship with the TblJewelleryInventory model (specifically to the pk field). So, when an instance of TblJewelleryInventory would try to traverse the reverse relationship for any one of the fields, it would try to use tbllockercoutcin_set in both cases -- which would result in ambiguity as both reverse relations are referred by the same name.

In this case, you want to use a related_name argument and set different accessor names for the fields e.g.:

jewel_item_code = models.ForeignKey(
    TblJewelleryInventory,
    on_delete=models.DO_NOTHING,
    related_name='jewel_item_code',  # Here
    db_column='jewel_item_code',
)
jewel_item_name = models.ForeignKey(
    TblJewelleryInventory,
    on_delete=models.DO_NOTHING,
    related_name='jewel_item_name',  # Here
    db_column='jewel_item_name',
)

Python Error : (fields.E304) Reverse accessor for field clashes with reverse accessor for another field

1 Answers