How to integrate Django with a legacy database¶
While Django is best suited for developing new applications, it’s quitepossible to integrate it into legacy databases. Django includes a couple ofutilities to automate as much of this process as possible.
This document assumes you know the Django basics, as covered in thetutorial.
Once you’ve got Django set up, you’ll follow this general process to integratewith an existing database.
Give Django your database parameters¶
You’ll need to tell Django what your database connection parameters are, andwhat the name of the database is. Do that by editing theDATABASESsetting and assigning values to the following keys for the'default'connection:
Auto-generate the models¶
Django comes with a utility calledinspectdb that can create modelsby introspecting an existing database. You can view the output by running thiscommand:
$pythonmanage.pyinspectdb
Save this as a file by using standard Unix output redirection:
$pythonmanage.pyinspectdb>models.py
This feature is meant as a shortcut, not as definitive model generation. Seethedocumentationofinspectdb for more information.
Once you’ve cleaned up your models, name the filemodels.py and put it inthe Python package that holds your app. Then add the app to yourINSTALLED_APPS setting.
By default,inspectdb creates unmanaged models. That is,managed=False in the model’sMeta class tells Django not to manageeach table’s creation, modification, and deletion:
classPerson(models.Model):id=models.IntegerField(primary_key=True)first_name=models.CharField(max_length=70)classMeta:managed=Falsedb_table="CENSUS_PERSONS"
If you do want to allow Django to manage the table’s lifecycle, you’ll need tochange themanaged option above toTrue(or remove it becauseTrue is its default value).
Install the core Django tables¶
Next, run themigrate command to install any extra needed databaserecords such as admin permissions and content types:
$pythonmanage.pymigrate
Test and tweak¶
Those are the basic steps – from here you’ll want to tweak the models Djangogenerated until they work the way you’d like. Try accessing your data via theDjango database API, and try editing objects via Django’s admin site, and editthe models file accordingly.
