django-import-export | issue in importing data to database | ValueError: Field 'id' expect-CodePudding

I am using Django-import-export for importing data but facing an error given below. i am using django 4.0.6 python 3.10.5 with PostgreSql and most latest version of django import export

Code settings i tried to import data to postgresql database by django-import-export

class MemberResource(resources.ModelResource):
    Brand=Field()
    class Meta:
        model = model
        fields=('id','title','Model_code','Chipset','chipset_description','image','Brand','Cat')
        export_order=('id','title','Model_code','Chipset','chipset_description','image','Brand','Cat')
    def dehydrate_Brand(self, obj):
        return str(obj.Brand.title)


class modelAdmin(ImportExportModelAdmin):
    resource_class = MemberResource
    list_display=['id','title','Model_code','Chipset','chipset_description','Brand','categories']
    search_fields = ['title','Model_code','Chipset',]
    fields=('title','Model_code','Chipset','chipset_description','image','Brand','Cat')
admin.site.register(model,modelAdmin)

and got below error also attached the image where i exported the data from app and then edited the same and tried to import and stuck with below error.

[Line number: 1 - Field 'id' expected a number but got ''.
2, f9, sd, gf, kjkj, images/sample_3pahsfV.jfif, 1, 1
Traceback (most recent call last):
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\django\db\models\fields\related_descriptors.py", line 187, in _get_
rel_obj = self.field.get_cached_value(instance)
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\django\db\models\fields\mixins.py", line 15, in get_cached_value
return instance._state.fields_cache\[cache_name\]
KeyError: 'Brand'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\django\db\models\fields\_init_.py", line 1988, in get_prep_value
return int(value)
ValueError: invalid literal for int() with base 10: ''

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\import_export\resources.py", line 707, in import_row
diff = self.get_diff_class()(self, original, new)
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\import_export\resources.py", line 241, in _init_
self.left = self._export_resource_fields(resource, instance)
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\import_export\resources.py", line 262, in _export_resource_fields
return \[resource.export_field(f, instance) if instance else "" for f in resource.get_user_visible_fields()\]
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\import_export\resources.py", line 262, in <listcomp>
return \[resource.export_field(f, instance) if instance else "" for f in resource.get_user_visible_fields()\]
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\import_export\resources.py", line 919, in export_field
return method(obj)
File "C:\Users\gsminfinity\Desktop\Master\admin\firmApp\admin.py", line 20, in dehydrate_Brand
return str(obj.Brand.title)
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\django\db\models\fields\related_descriptors.py", line 205, in _get_
rel_obj = self.get_object(instance)
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\django\db\models\fields\related_descriptors.py", line 168, in get_object
return qs.get(self.field.get_reverse_related_filter(instance))
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\django\db\models\query.py", line 482, in get
clone = self._chain() if self.query.combinator else self.filter(*args, **kwargs)
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\django\db\models\query.py", line 1071, in filter
return self._filter_or_exclude(False, args, kwargs)
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\django\db\models\query.py", line 1089, in _filter_or_exclude
clone._filter_or_exclude_inplace(negate, args, kwargs)
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\django\db\models\query.py", line 1096, in _filter_or_exclude_inplace
self._query.add_q(Q(*args, **kwargs))
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\django\db\models\sql\query.py", line 1502, in add_q
clause, _ = self._add_q(q_object, self.used_aliases)
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\django\db\models\sql\query.py", line 1532, in _add_q
child_clause, needed_inner = self.build_filter(
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\django\db\models\sql\query.py", line 1358, in build_filter
return self._add_q(
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\django\db\models\sql\query.py", line 1532, in _add_q
child_clause, needed_inner = self.build_filter(
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\django\db\models\sql\query.py", line 1448, in build_filter
condition = self.build_lookup(lookups, col, value)
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\django\db\models\sql\query.py", line 1273, in build_lookup
lookup = lookup_class(lhs, rhs)
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\django\db\models\lookups.py", line 27, in _init_
self.rhs = self.get_prep_lookup()
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\django\db\models\lookups.py", line 85, in get_prep_lookup
return self.lhs.output_field.get_prep_value(self.rhs)
File "C:\Users\gsminfinity\Desktop\Master\venv\lib\site-packages\django\db\models\fields\_init_.py", line 1990, in get_prep_value
raise e._class_(
ValueError: Field 'id' expected a number but got ''.][1]

CodePudding user response：

That means that there are missing values in the "id" column.

I don't know "Django import / export", sounds very good. An old way of mine with any import/export is to export some sample data and then open it in excel or pandas. Because of the following:

You have all the required columns.
The columns are in the correct order.
And if you have test data you can see the data-types of each column.

Take care using Excel because it changes True into TRUE and generates weird date formats. Another issue is that after importing django u must also be aware of the last "id" number in order to give the correct AutoIncrement for a new record. That's usually corrected with SQL, but maybe "Django-import-export" corrects this automatically.

CodePudding user response：

the issue was dehydrating foreign key gives only read-only data which was for the purpose of export only to import we need to use the widgets which will resolve the foreign keys and import the data to database.

Link to Documentation

class MemberResource(resources.ModelResource):
    Brand = fields.Field(
        column_name='Brand',
        attribute='Brand',
        widget=ForeignKeyWidget(brand, 'title'))
    class Meta:
        model = model
        fields=('id','title','Model_code','Chipset','chipset_description','image','Brand','Cat')