Django merge duplicate rows

To merge duplicate rows in Django, you can follow these steps:

1. Identify the duplicate rows: Use Django's query methods to identify the duplicate rows in your database table. You can use the values() method to select specific fields and the annotate() method to count the occurrences of each field combination. For example:

duplicate_rows = YourModel.objects.values('field1', 'field2').annotate(count=Count('id')).filter(count__gt=1)

1. Create a dictionary of unique values: Iterate over the duplicate_rows queryset and create a dictionary of unique values for each field combination. This dictionary will act as a reference for merging the duplicate rows. For example:

unique_values = {}
for row in duplicate_rows:
    field1_value = row['field1']
    field2_value = row['field2']
    if (field1_value, field2_value) not in unique_values:
        unique_values[(field1_value, field2_value)] = YourModel.objects.filter(field1=field1_value, field2=field2_value).first()

1. Merge the duplicate rows: Iterate over the duplicate_rows queryset again and update the duplicate rows with the unique values from the dictionary. For example:

for row in duplicate_rows:
    field1_value = row['field1']
    field2_value = row['field2']
    duplicate_rows_to_merge = YourModel.objects.filter(field1=field1_value, field2=field2_value).exclude(id=unique_values[(field1_value, field2_value)].id)
    for duplicate_row in duplicate_rows_to_merge:
        # Update any related fields or perform any necessary operations here
        duplicate_row.delete()

1. Save the changes: After merging the duplicate rows, save the changes to the database. For example:

YourModel.objects.bulk_update(unique_values.values(), ['field1', 'field2'])

By following these steps, you can effectively merge duplicate rows in Django. Make sure to adapt the code to your specific model and field names.