Dry ORM

Code

Result

no cache

from django.db import models

class Record(models.Model):
    x = models.CharField(max_length=10, null=True)
    y = models.CharField(max_length=10, null=True)
    z = models.CharField(max_length=10, null=True)

class Meta:
        constraints = [
            models.UniqueConstraint(
                models.functions.Coalesce('x', models.Value('')),
                models.functions.Coalesce('y', models.Value('')),
                models.functions.Coalesce('z', models.Value('')),
                name='unique_xyz_treat_null_as_empty'
            )
        ]

def run():
    try:
        Record.objects.create(x='a', y='b', z='c')
        Record.objects.create(x='a', y='b', z='c')
    except Exception as e:
        print(f"Duplicate prevented for same triple")

try:
        Record.objects.create(x=None, y='b', z='c')
        Record.objects.create(x=None, y='b', z='c')
    except Exception as e:
        print(f"Duplicate prevented for NULLs too")

# Show all
    for r in Record.objects.all():
        print(r.id, r.x, r.y, r.z)

Output

No output.

Queries

Queries Q (0)

No queries.