django custom unique_together constraint name.

named_indices__models.py

# named_indices/models.py

from django.db.backends.schema import BaseDatabaseSchemaEditor

old_create_index_name = BaseDatabaseSchemaEditor._create_index_name
if not hasattr(BaseDatabaseSchemaEditor, '_old_create_index_name'):
    setattr(BaseDatabaseSchemaEditor, '_old_create_index_name', old_create_index_name)

def _create_index_name(self, model, column_names, suffix=""):
    try:
        return model._meta._index_names[column_names]
    except (KeyError, AttributeError, TypeError):
        # KeyError - index name not defined for tuple
        # AttributeError - _index_names not defined on model._meta
        # TypeError - not using hashable key (e.g. list instead of tuple)
        return self._old_create_index_name(model, column_names, suffix)

setattr(BaseDatabaseSchemaEditor, '_create_index_name', _create_index_name)

settings.py

INSTALLED_APPS += ('named_indices',)

testapp__models.py

# testapp/models.py

from django.db import models

class MyModel(models.Model):
    clid = models.AutoField(primary_key=True, db_column='CLID')
    csid = models.IntegerField(db_column='CSID')
    cid = models.IntegerField(db_column='CID')
    uuid = models.CharField(max_length=96, db_column='UUID', blank=True)

    class Meta:
        unique_together = [
            ("csid", "cid", "uuid"),
        ]
        _index_names = {
            ("csid", "cid", "uuid"): 'custom_index_name',
        }

Cool hack, thanks for it