Troubleshooting “Related Field has invalid lookup: icontains”

Question

I have the following models in models.py:

class ListinoTraduttore(models.Model):
        traduttore = models.ForeignKey(\'Traduttore\', related_name=         


        

Answer 1

This may not answer the original question, but, every so often I run into a similar invalid lookup error because I accidentally used _set in a lookup, e.g. <model_name>_set instead of just <model_name>.

Basically, I tend to confuse the related_query_name with the default_related_name , which does include _set (also see queries docs and related manager docs).

From the lookups documentation:

It works backwards, too. Whilst it can be customized, by default you refer to a “reverse” relationship in a lookup using the lowercase name of the model.

(my emphasis)

Confusing thing is that the default related_name (i.e. <model_name>_set) is not the same as the default related_query_name (i.e. <model_name>), but if you set a custom related_name (or default_related_name, via model Meta options), that will also be used as the default related_query_name (as mentioned in the docs).

Answer 2

Make sure you are not adding any Foreignkey or ManyToManyField to your search_field directly.

Use Django's double underscore convention instead. docs

class ListinoTraduttoreAdmin(admin.ModelAdmin):
    list_display = ("traduttore", "linguaDa", "linguaA", "prezzoParola", "prezzoRiga", "scontoCat", "scontoFuzzy", "scontoRipetizioni")
    search_fields = ['traduttore__nome", "linguaDa__field1", "linguaA__field2"]

Answer 3

Double underscore needed

class exampleAdmin(admin.ModelAdmin):
 search_field = ('yourforeignkeyname__choosefieldnameinyourforeignkey')

Answer 4

This is to (hopefully) simplify the answer.

Don't filter on a ForeignKey field itself!

Change this

search_fields = ['foreinkeyfield']

to (notice TWO underscores)

search_fields = ['foreinkeyfield__name']

name represents the field-name from the table that we have a ForeinKey relationship with.

Hope this helps

Answer 5

This worked for me.

Search the field of the foreign key using my_related_object__first_attribute:

search_fields = ('author__username', 'title')
from models
author = models.ForeignKey(User, on_delete=models.CASCADE,   related_name='blog_posts2')

Answer 6

add in admin.py

admin.site.register(Traduttore, TraduttoreAdmin)
admin.site.register(ListinoTraduttore, ListinoTraduttoreAdmin)

see the link https://docs.djangoproject.com/en/dev/intro/tutorial02/