PookieDB Refresher

Before wiring PookieDB to the frontend, let's make sure the database side is solid. You covered this earlier - this page is a quick recap with one update: we are now using UUIDs as the primary key instead of integers.

---

Why UUIDs

An integer id counts up: 1, 2, 3. If you know patient 3 exists, you can guess that patient 4 probably does too. That makes integer ids easy to enumerate.

A UUID looks like this: f47ac10b-58cc-4372-a567-0e02b2c3d479. It is randomly generated and practically impossible to guess. Better for any situation where records have ids that end up in URLs.

---

The updated model

Add id = pookiedb.UUIDField(auto=True, primary_key=True) to your model. PookieDB generates the UUID automatically every time you create a record - you never set it yourself.

import pookiedb

pookiedb.connect("sqlite:///patients.sqlite3")

class Patient(pookiedb.Model):
    id   = pookiedb.UUIDField(auto=True, primary_key=True)
    name = pookiedb.CharField(max_length=100)
    age  = pookiedb.IntegerField()

    class Meta:
        db_table = "patients"

Patient.create_table()

---

Create

Patient.objects.create(name="Alice", age=24)
Patient.objects.create(name="Bob", age=31)

The id is assigned automatically. You do not pass it in.

---

Read all

patients = Patient.objects.all()

for patient in patients:
    print(patient.id, patient.name, patient.age)

patient.id is a UUID object. To use it as a string (in a URL or JSON), convert it: str(patient.id).

---

Read one

patient = Patient.objects.get(id="f47ac10b-58cc-4372-a567-0e02b2c3d479")
print(patient.name)

Pass the UUID as a string. PookieDB handles the conversion.

---

Filter

results = Patient.objects.filter(name="Alice")
for p in results:
    print(p.name, p.age)

Returns all rows where the name matches. You can filter by any field.

---

Update

Patient.objects.filter(id="f47ac10b-...").bulk_update(age=25)

Chain filter() to find the record, then bulk_update() with the new values. Note: it is bulk_update, not update.

---

Delete one record

Patient.objects.filter(id="f47ac10b-...").delete()

Permanently removes that row from the database.

---

Delete many records

Patient.objects.filter(name="Alice").delete()

Removes every row where name is "Alice".

---

Count

Patient.objects.all().count()   # total rows in the table
Patient.objects.filter(name="Alice").count()   # rows matching a filter

---

Challenge

In a fresh main.py, do all of this:

1. Add two patients
2. Print both of them with their UUIDs
3. Update the age of the first one using its UUID
4. Delete the second one
5. Print the count - it should be 1
6. Stop and restart the script - is the remaining patient still there?

---

← HTTP Methods    Next: Create - Sending Data →