diff options
Diffstat (limited to 'django/db/models')
| -rw-r--r-- | django/db/models/base.py | 2 | ||||
| -rw-r--r-- | django/db/models/constraints.py | 34 |
2 files changed, 30 insertions, 6 deletions
diff --git a/django/db/models/base.py b/django/db/models/base.py index b55c5a32b1..faed79cc2f 100644 --- a/django/db/models/base.py +++ b/django/db/models/base.py @@ -1009,6 +1009,8 @@ class Model(metaclass=ModelBase): for model_class, model_constraints in constraints: for constraint in model_constraints: if (isinstance(constraint, UniqueConstraint) and + # Partial unique constraints can't be validated. + constraint.condition is None and not any(name in exclude for name in constraint.fields)): unique_checks.append((model_class, constraint.fields)) diff --git a/django/db/models/constraints.py b/django/db/models/constraints.py index 5b6f498d94..e7f81d3ee9 100644 --- a/django/db/models/constraints.py +++ b/django/db/models/constraints.py @@ -1,3 +1,4 @@ +from django.db.models.query_utils import Q from django.db.models.sql.query import Query __all__ = ['CheckConstraint', 'UniqueConstraint'] @@ -66,34 +67,55 @@ class CheckConstraint(BaseConstraint): class UniqueConstraint(BaseConstraint): - def __init__(self, *, fields, name): + def __init__(self, *, fields, name, condition=None): if not fields: raise ValueError('At least one field is required to define a unique constraint.') + if not isinstance(condition, (type(None), Q)): + raise ValueError('UniqueConstraint.condition must be a Q instance.') self.fields = tuple(fields) + self.condition = condition super().__init__(name) + def _get_condition_sql(self, model, schema_editor): + if self.condition is None: + return None + query = Query(model=model) + where = query.build_where(self.condition) + compiler = query.get_compiler(connection=schema_editor.connection) + sql, params = where.as_sql(compiler, schema_editor.connection) + return sql % tuple(schema_editor.quote_value(p) for p in params) + def constraint_sql(self, model, schema_editor): fields = [model._meta.get_field(field_name).column for field_name in self.fields] - return schema_editor._unique_sql(fields, self.name) + condition = self._get_condition_sql(model, schema_editor) + return schema_editor._unique_sql(model, fields, self.name, condition=condition) def create_sql(self, model, schema_editor): fields = [model._meta.get_field(field_name).column for field_name in self.fields] - return schema_editor._create_unique_sql(model, fields, self.name) + condition = self._get_condition_sql(model, schema_editor) + return schema_editor._create_unique_sql(model, fields, self.name, condition=condition) def remove_sql(self, model, schema_editor): - return schema_editor._delete_unique_sql(model, self.name) + condition = self._get_condition_sql(model, schema_editor) + return schema_editor._delete_unique_sql(model, self.name, condition=condition) def __repr__(self): - return '<%s: fields=%r name=%r>' % (self.__class__.__name__, self.fields, self.name) + return '<%s: fields=%r name=%r%s>' % ( + self.__class__.__name__, self.fields, self.name, + '' if self.condition is None else ' condition=%s' % self.condition, + ) def __eq__(self, other): return ( isinstance(other, UniqueConstraint) and self.name == other.name and - self.fields == other.fields + self.fields == other.fields and + self.condition == other.condition ) def deconstruct(self): path, args, kwargs = super().deconstruct() kwargs['fields'] = self.fields + if self.condition: + kwargs['condition'] = self.condition return path, args, kwargs |