When building a Django application that requires storing users’ phone numbers, one decision developers need to make is how to best represent those phone numbers in the database. There are a few different approaches, each with their own pros and cons. In this post, we will compare the options and make a recommendation for the best way to store phone numbers in Django models.
Normalize Data Upon Input – Phone Numbers
First, it’s important to normalize phone number data as it is input by users. This means removing unnecessary characters like parentheses, dashes, and spaces so the number is stored in a consistent format. Django provides validators that can help with this.
For example, Django’s PhoneNumberField can validate and normalize input values so they are stored without extraneous characters. This makes them easier to work with in the database and business logic.
The Character Field Option- Phone Numbers
One option is to use a character field like CharField to store phone numbers. This allows maximum flexibility in terms of input formats. However, it means the data is not validated on input and numbers may not be consistently formatted in the database. For example:
from django.db import models
class Contact(models.Model):
phone_number = models.CharField(max_length=20) While simple, this approach has downsides:
- No validation or normalization, leading to inconsistent data
- Requires custom logic to format numbers before display or use
- No way to identify numbers asPhone numbers for validation in forms
Overall, using a simple character field offers flexibility but makes working with and validatingPhone number data more difficult.
The Integer Field Option
Another approach is storingPhone numbers as big integers, removing any non-numeric characters on input. For example:
from django.db import models
class Contact(models.Model):
phone_number = models.BigIntegerField()This effectively normalizes data but has some drawbacks:
- Loses country code information which may be needed in some cases
- Requires custom display logic to add formatting back for user display
- Data validation is still limited
In general, storingphone numbers as integers makes some operations easier but removes too much context.
The Phone Number Field
Django third-party packages like django-phonenumber-field provide a PhoneNumberField model field. This offers:
- Validation on input using googlelibphonenumber to reject invalid numbers
- Normalization into E.164 standard international format
- Parsing output into national or international formats
- Identification as phone number for forms API
Here is an example using django-phonenumber-field:
from phonenumber_field.modelfields import PhoneNumberField
class Contact(models.Model):
phone_number = PhoneNumberField()This requires installing the package but then handles much of the validation and normalization automatically. It’s the easiest way to properly handle phone numbers in Django models.
Recommendation
Based on the above comparison, the PhoneNumberField from django-phonenumber-field is likely the best approach for most use cases. The key advantages are:
- Validates against invalid input using google phone number library
- Normalizes data to enable easier processing and analysis
- Flexible display formatting while retaining original validated data
- Integrates with forms for automatic phone number widgets
Conclusion
Properly storing and validating phone numbers in web applications requires some care. In Django, using a purpose-built PhoneNumberField like django-phonenumber-field saves time and prevents data quality issues down the line.
As with any package, evaluate if it fits your specific needs. But for most applications needing to collect phone numbers, a field designed specially for phone numbers is worth utilizing. With the data appropriately validated and normalized, you can focus on building features rather than display formatting.
