Django admin: search for foreign key objects rather than <select>?

Did you take a look at raw_id_fields?

It should be pretty to close to what you're after.

If you are using Django >= 2.0, you can take advantage of a feature called autocomplete_fields. You must define search_fields on the related object’s ModelAdmin because the autocomplete search uses it.

Since you have a ForeignKey relationship to Asset in WorkOrder, in the admin.py of your app add the following:

from django.contrib import admin

@admin.register(Asset)
class AssetAdmin(admin.ModelAdmin):
    search_fields = ["serial_number", "asset_tag"]


@admin.register(WorkOrder)
class WorkOrderAdmin(admin.ModelAdmin):
    autocomplete_fields = ["asset"]

Add the fields you want to use for searching to search_fields, and add define autocomplete_fields as shown in the code above.