# models.mixins.relation\_mixin
## RelationMixin Objects
```python
class RelationMixin()
```
Used to return relation fields/names etc. from given model
#### extract\_db\_own\_fields
```python
| @classmethod
| extract_db_own_fields(cls) -> Set
```
Returns only fields that are stored in the own database table, exclude all
related fields.
**Returns**:
`(Set)`: set of model fields with relation fields excluded
#### extract\_related\_fields
```python
| @classmethod
| extract_related_fields(cls) -> List["ForeignKeyField"]
```
Returns List of ormar Fields for all relations declared on a model.
List is cached in cls._related_fields for quicker access.
**Returns**:
`(List)`: list of related fields
#### extract\_through\_names
```python
| @classmethod
| extract_through_names(cls) -> Set[str]
```
Extracts related fields through names which are shortcuts to through models.
**Returns**:
`(Set)`: set of related through fields names
#### extract\_related\_names
```python
| @classmethod
| extract_related_names(cls) -> Set[str]
```
Returns List of fields names for all relations declared on a model.
List is cached in cls._related_names for quicker access.
**Returns**:
`(Set)`: set of related fields names
#### \_extract\_db\_related\_names
```python
| @classmethod
| _extract_db_related_names(cls) -> Set
```
Returns only fields that are stored in the own database table, exclude
related fields that are not stored as foreign keys on given model.
**Returns**:
`(Set)`: set of model fields with non fk relation fields excluded
#### \_iterate\_related\_models
```python
| @classmethod
| _iterate_related_models(cls, node_list: NodeList = None, source_relation: str = None) -> List[str]
```
Iterates related models recursively to extract relation strings of
nested not visited models.
**Returns**:
`(List[str])`: list of relation strings to be passed to select_related
#### \_get\_final\_relations
```python
| @staticmethod
| _get_final_relations(processed_relations: List, source_relation: Optional[str]) -> List[str]
```
Helper method to prefix nested relation strings with current source relation
**Arguments**:
- `processed_relations (List[str])`: list of already processed relation str
- `source_relation (str)`: name of the current relation
**Returns**:
`(List[str])`: list of relation strings to be passed to select_related