Many to One¶
A many to one relationship associates many children with a single parent. For example, a company can have many employees working in the same division (for example engineering, legal, marketing, …) but a particular employee can only work in one division.
See also
- Many to One
OpenAlchemy documentation for many to one relationships.
- SQLAlchemy Many to One
SQLAlchemy documentation for many to one relationships.
The following example defines a many to one relationship between Employee and Division:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 | openapi: "3.0.0" info: title: Test Schema description: API to illustrate Many to One Relationships. version: "0.1" paths: /division: get: summary: Used to retrieve all divisions. responses: 200: description: Return all divisions from the database. content: application/json: schema: type: array items: "$ref": "#/components/schemas/Division" /employee: get: summary: Used to retrieve all employees. responses: 200: description: Return all employees from the database. content: application/json: schema: type: array items: "$ref": "#/components/schemas/Employee" components: schemas: Division: description: A part of a company. type: object x-tablename: division properties: id: type: integer description: Unique identifier for the division. example: 0 x-primary-key: true name: type: string description: The name of the division. example: Engineering Employee: description: Person that works for a company. type: object x-tablename: employee properties: id: type: integer description: Unique identifier for the employee. example: 0 x-primary-key: true name: type: string description: The name of the employee. example: David Andersson division: "$ref": "#/components/schemas/Division" |
The following file uses OpenAlchemy to generate the SQLAlchemy models:
1 2 3 | from open_alchemy import init_yaml init_yaml("example-spec.yml", models_filename="models_auto.py") |
The SQLAlchemy models generated by OpenAlchemy are equivalent to the following traditional models file:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 | import sqlalchemy as sa from sqlalchemy.ext.declarative import declarative_base Base = declarative_base() class Division(Base): """Division of a company.""" __tablename__ = "division" id = sa.Column(sa.Integer, primary_key=True) name = sa.Column(sa.String) class Employee(Base): """Person that works for a company.""" __tablename__ = "employee" id = sa.Column(sa.Integer, primary_key=True) name = sa.Column(sa.String) division = sa.orm.relationship("Division") division_id = sa.Column(sa.Integer, sa.ForeignKey("division.id")) |
OpenAlchemy will generate the following typed models:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 | """Autogenerated SQLAlchemy models based on OpenAlchemy models.""" # pylint: disable=no-member,super-init-not-called,unused-argument import typing import sqlalchemy from sqlalchemy import orm from open_alchemy import models Base = models.Base # type: ignore class DivisionDict(typing.TypedDict, total=False): """TypedDict for properties that are not required.""" id: typing.Optional[int] name: typing.Optional[str] class TDivision(typing.Protocol): """ SQLAlchemy model protocol. A part of a company. Attrs: id: Unique identifier for the division. name: The name of the division. """ # SQLAlchemy properties __table__: sqlalchemy.Table __tablename__: str query: orm.Query # Model properties id: "sqlalchemy.Column[typing.Optional[int]]" name: "sqlalchemy.Column[typing.Optional[str]]" def __init__( self, id: typing.Optional[int] = None, name: typing.Optional[str] = None ) -> None: """ Construct. Args: id: Unique identifier for the division. name: The name of the division. """ ... @classmethod def from_dict( cls, id: typing.Optional[int] = None, name: typing.Optional[str] = None ) -> "TDivision": """ Construct from a dictionary (eg. a POST payload). Args: id: Unique identifier for the division. name: The name of the division. Returns: Model instance based on the dictionary. """ ... @classmethod def from_str(cls, value: str) -> "TDivision": """ Construct from a JSON string (eg. a POST payload). Returns: Model instance based on the JSON string. """ ... def to_dict(self) -> DivisionDict: """ Convert to a dictionary (eg. to send back for a GET request). Returns: Dictionary based on the model instance. """ ... def to_str(self) -> str: """ Convert to a JSON string (eg. to send back for a GET request). Returns: JSON string based on the model instance. """ ... Division: typing.Type[TDivision] = models.Division # type: ignore class EmployeeDict(typing.TypedDict, total=False): """TypedDict for properties that are not required.""" id: typing.Optional[int] name: typing.Optional[str] division: typing.Optional["DivisionDict"] class TEmployee(typing.Protocol): """ SQLAlchemy model protocol. Person that works for a company. Attrs: id: Unique identifier for the employee. name: The name of the employee. division: The division of the Employee. """ # SQLAlchemy properties __table__: sqlalchemy.Table __tablename__: str query: orm.Query # Model properties id: "sqlalchemy.Column[typing.Optional[int]]" name: "sqlalchemy.Column[typing.Optional[str]]" division: 'sqlalchemy.Column[typing.Optional["TDivision"]]' def __init__( self, id: typing.Optional[int] = None, name: typing.Optional[str] = None, division: typing.Optional["TDivision"] = None, ) -> None: """ Construct. Args: id: Unique identifier for the employee. name: The name of the employee. division: The division of the Employee. """ ... @classmethod def from_dict( cls, id: typing.Optional[int] = None, name: typing.Optional[str] = None, division: typing.Optional["DivisionDict"] = None, ) -> "TEmployee": """ Construct from a dictionary (eg. a POST payload). Args: id: Unique identifier for the employee. name: The name of the employee. division: The division of the Employee. Returns: Model instance based on the dictionary. """ ... @classmethod def from_str(cls, value: str) -> "TEmployee": """ Construct from a JSON string (eg. a POST payload). Returns: Model instance based on the JSON string. """ ... def to_dict(self) -> EmployeeDict: """ Convert to a dictionary (eg. to send back for a GET request). Returns: Dictionary based on the model instance. """ ... def to_str(self) -> str: """ Convert to a JSON string (eg. to send back for a GET request). Returns: JSON string based on the model instance. """ ... Employee: typing.Type[TEmployee] = models.Employee # type: ignore |
Nullable¶
The OpenAPI nullable directive can be used to control the nullability of the many to one relationship.
See also
- Nullable
OpenAlchemy documentation for the nullability of many to one relationships.
The following example defines a many to one relationship between Employee and Division that is not nullable:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 | openapi: "3.0.0" info: title: Test Schema description: API to illustrate Many to One Relationships that are not nullable. version: "0.1" paths: /division: get: summary: Used to retrieve all divisions. responses: 200: description: Return all divisions from the database. content: application/json: schema: type: array items: "$ref": "#/components/schemas/Division" /employee: get: summary: Used to retrieve all employees. responses: 200: description: Return all employees from the database. content: application/json: schema: type: array items: "$ref": "#/components/schemas/Employee" components: schemas: Division: description: A part of a company. type: object x-tablename: division properties: id: type: integer description: Unique identifier for the division. example: 0 x-primary-key: true name: type: string description: The name of the division. example: Engineering Employee: description: Person that works for a company. type: object x-tablename: employee properties: id: type: integer description: Unique identifier for the employee. example: 0 x-primary-key: true name: type: string description: The name of the employee. example: David Andersson division: allOf: - "$ref": "#/components/schemas/Division" - nullable: False |
The following file uses OpenAlchemy to generate the SQLAlchemy models:
1 2 3 4 5 | from open_alchemy import init_yaml init_yaml( "not-nullable-example-spec.yml", models_filename="not_nullable_models_auto.py" ) |
The SQLAlchemy models generated by OpenAlchemy are equivalent to the following traditional models file:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 | import sqlalchemy as sa from sqlalchemy.ext.declarative import declarative_base Base = declarative_base() class Division(Base): """Division of a company.""" __tablename__ = "division" id = sa.Column(sa.Integer, primary_key=True) name = sa.Column(sa.String) class Employee(Base): """Person that works for a company.""" __tablename__ = "employee" id = sa.Column(sa.Integer, primary_key=True) name = sa.Column(sa.String) division_id = sa.Column(sa.Integer, sa.ForeignKey("division.id"), nullable=False) |
OpenAlchemy will generate the following typed models:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 | """Autogenerated SQLAlchemy models based on OpenAlchemy models.""" # pylint: disable=no-member,super-init-not-called,unused-argument import typing import sqlalchemy from sqlalchemy import orm from open_alchemy import models Base = models.Base # type: ignore class DivisionDict(typing.TypedDict, total=False): """TypedDict for properties that are not required.""" id: typing.Optional[int] name: typing.Optional[str] class TDivision(typing.Protocol): """ SQLAlchemy model protocol. A part of a company. Attrs: id: Unique identifier for the division. name: The name of the division. """ # SQLAlchemy properties __table__: sqlalchemy.Table __tablename__: str query: orm.Query # Model properties id: "sqlalchemy.Column[typing.Optional[int]]" name: "sqlalchemy.Column[typing.Optional[str]]" def __init__( self, id: typing.Optional[int] = None, name: typing.Optional[str] = None ) -> None: """ Construct. Args: id: Unique identifier for the division. name: The name of the division. """ ... @classmethod def from_dict( cls, id: typing.Optional[int] = None, name: typing.Optional[str] = None ) -> "TDivision": """ Construct from a dictionary (eg. a POST payload). Args: id: Unique identifier for the division. name: The name of the division. Returns: Model instance based on the dictionary. """ ... @classmethod def from_str(cls, value: str) -> "TDivision": """ Construct from a JSON string (eg. a POST payload). Returns: Model instance based on the JSON string. """ ... def to_dict(self) -> DivisionDict: """ Convert to a dictionary (eg. to send back for a GET request). Returns: Dictionary based on the model instance. """ ... def to_str(self) -> str: """ Convert to a JSON string (eg. to send back for a GET request). Returns: JSON string based on the model instance. """ ... Division: typing.Type[TDivision] = models.Division # type: ignore class EmployeeDict(typing.TypedDict, total=False): """TypedDict for properties that are not required.""" id: typing.Optional[int] name: typing.Optional[str] division: "DivisionDict" class TEmployee(typing.Protocol): """ SQLAlchemy model protocol. Person that works for a company. Attrs: id: Unique identifier for the employee. name: The name of the employee. division: The division of the Employee. """ # SQLAlchemy properties __table__: sqlalchemy.Table __tablename__: str query: orm.Query # Model properties id: "sqlalchemy.Column[typing.Optional[int]]" name: "sqlalchemy.Column[typing.Optional[str]]" division: 'sqlalchemy.Column["TDivision"]' def __init__( self, id: typing.Optional[int] = None, name: typing.Optional[str] = None, division: typing.Optional["TDivision"] = None, ) -> None: """ Construct. Args: id: Unique identifier for the employee. name: The name of the employee. division: The division of the Employee. """ ... @classmethod def from_dict( cls, id: typing.Optional[int] = None, name: typing.Optional[str] = None, division: typing.Optional["DivisionDict"] = None, ) -> "TEmployee": """ Construct from a dictionary (eg. a POST payload). Args: id: Unique identifier for the employee. name: The name of the employee. division: The division of the Employee. Returns: Model instance based on the dictionary. """ ... @classmethod def from_str(cls, value: str) -> "TEmployee": """ Construct from a JSON string (eg. a POST payload). Returns: Model instance based on the JSON string. """ ... def to_dict(self) -> EmployeeDict: """ Convert to a dictionary (eg. to send back for a GET request). Returns: Dictionary based on the model instance. """ ... def to_str(self) -> str: """ Convert to a JSON string (eg. to send back for a GET request). Returns: JSON string based on the model instance. """ ... Employee: typing.Type[TEmployee] = models.Employee # type: ignore |
Backref¶
SQLAlchemy allows for back references so that the on the child side of the relationship the parent model is also accessible.
See also
- Backref
OpenAlchemy documentation for back references.
The following example defines a many to one relationship between Employee and Division that includes a back reference on Division to Employee:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 | openapi: "3.0.0" info: title: Test Schema description: API to illustrate Many to One Relationships with back references. version: "0.1" paths: /division: get: summary: Used to retrieve all divisions. responses: 200: description: Return all divisions from the database. content: application/json: schema: type: array items: "$ref": "#/components/schemas/Division" /employee: get: summary: Used to retrieve all employees. responses: 200: description: Return all employees from the database. content: application/json: schema: type: array items: "$ref": "#/components/schemas/Employee" components: schemas: Division: description: A part of a company. type: object x-tablename: division properties: id: type: integer description: Unique identifier for the division. example: 0 x-primary-key: true name: type: string description: The name of the division. example: Engineering Employee: description: Person that works for a company. type: object x-tablename: employee properties: id: type: integer description: Unique identifier for the employee. example: 0 x-primary-key: true name: type: string description: The name of the employee. example: David Andersson division: allOf: - "$ref": "#/components/schemas/Division" - x-backref: employees |
The following file uses OpenAlchemy to generate the SQLAlchemy models:
1 2 3 | from open_alchemy import init_yaml init_yaml("backref-example-spec.yml", models_filename="backref_models_auto.py") |
The SQLAlchemy models generated by OpenAlchemy are equivalent to the following traditional models file:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 | import sqlalchemy as sa from sqlalchemy.ext.declarative import declarative_base Base = declarative_base() class Division(Base): """Division of a company.""" __tablename__ = "division" id = sa.Column(sa.Integer, primary_key=True) name = sa.Column(sa.String) class Employee(Base): """Person that works for a company.""" __tablename__ = "employee" id = sa.Column(sa.Integer, primary_key=True) name = sa.Column(sa.String) division = sa.orm.relationship("Division", backref="employees") division_id = sa.Column(sa.Integer, sa.ForeignKey("division.id")) |
OpenAlchemy will generate the following typed models:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 | """Autogenerated SQLAlchemy models based on OpenAlchemy models.""" # pylint: disable=no-member,super-init-not-called,unused-argument import typing import sqlalchemy from sqlalchemy import orm from open_alchemy import models Base = models.Base # type: ignore class DivisionDict(typing.TypedDict, total=False): """TypedDict for properties that are not required.""" id: typing.Optional[int] name: typing.Optional[str] class TDivision(typing.Protocol): """ SQLAlchemy model protocol. A part of a company. Attrs: id: Unique identifier for the division. name: The name of the division. employees: The employees of the Division. """ # SQLAlchemy properties __table__: sqlalchemy.Table __tablename__: str query: orm.Query # Model properties id: "sqlalchemy.Column[typing.Optional[int]]" name: "sqlalchemy.Column[typing.Optional[str]]" employees: 'sqlalchemy.Column[typing.Sequence["TEmployee"]]' def __init__( self, id: typing.Optional[int] = None, name: typing.Optional[str] = None, employees: typing.Optional[typing.Sequence["TEmployee"]] = None, ) -> None: """ Construct. Args: id: Unique identifier for the division. name: The name of the division. employees: The employees of the Division. """ ... @classmethod def from_dict( cls, id: typing.Optional[int] = None, name: typing.Optional[str] = None ) -> "TDivision": """ Construct from a dictionary (eg. a POST payload). Args: id: Unique identifier for the division. name: The name of the division. employees: The employees of the Division. Returns: Model instance based on the dictionary. """ ... @classmethod def from_str(cls, value: str) -> "TDivision": """ Construct from a JSON string (eg. a POST payload). Returns: Model instance based on the JSON string. """ ... def to_dict(self) -> DivisionDict: """ Convert to a dictionary (eg. to send back for a GET request). Returns: Dictionary based on the model instance. """ ... def to_str(self) -> str: """ Convert to a JSON string (eg. to send back for a GET request). Returns: JSON string based on the model instance. """ ... Division: typing.Type[TDivision] = models.Division # type: ignore class EmployeeDict(typing.TypedDict, total=False): """TypedDict for properties that are not required.""" id: typing.Optional[int] name: typing.Optional[str] division: typing.Optional["DivisionDict"] class TEmployee(typing.Protocol): """ SQLAlchemy model protocol. Person that works for a company. Attrs: id: Unique identifier for the employee. name: The name of the employee. division: The division of the Employee. """ # SQLAlchemy properties __table__: sqlalchemy.Table __tablename__: str query: orm.Query # Model properties id: "sqlalchemy.Column[typing.Optional[int]]" name: "sqlalchemy.Column[typing.Optional[str]]" division: 'sqlalchemy.Column[typing.Optional["TDivision"]]' def __init__( self, id: typing.Optional[int] = None, name: typing.Optional[str] = None, division: typing.Optional["TDivision"] = None, ) -> None: """ Construct. Args: id: Unique identifier for the employee. name: The name of the employee. division: The division of the Employee. """ ... @classmethod def from_dict( cls, id: typing.Optional[int] = None, name: typing.Optional[str] = None, division: typing.Optional["DivisionDict"] = None, ) -> "TEmployee": """ Construct from a dictionary (eg. a POST payload). Args: id: Unique identifier for the employee. name: The name of the employee. division: The division of the Employee. Returns: Model instance based on the dictionary. """ ... @classmethod def from_str(cls, value: str) -> "TEmployee": """ Construct from a JSON string (eg. a POST payload). Returns: Model instance based on the JSON string. """ ... def to_dict(self) -> EmployeeDict: """ Convert to a dictionary (eg. to send back for a GET request). Returns: Dictionary based on the model instance. """ ... def to_str(self) -> str: """ Convert to a JSON string (eg. to send back for a GET request). Returns: JSON string based on the model instance. """ ... Employee: typing.Type[TEmployee] = models.Employee # type: ignore |
Custom Foreign Key Column¶
By default, OpenAlchemy will pick the id property to construct the underlying foreign key constraint for a relationship. This can be changed using the x-foreign-key-column extension property.
See also
- Custom Foreign Key
OpenAlchemy documentation for custom foreign key columns.
The following example defines a many to one relationship between Employee and Division where the name column is used instead of the id column to construct the foreign key:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 | openapi: "3.0.0" info: title: Test Schema description: API to illustrate Many to One Relationships with custom foreign keys. version: "0.1" paths: /division: get: summary: Used to retrieve all divisions. responses: 200: description: Return all divisions from the database. content: application/json: schema: type: array items: "$ref": "#/components/schemas/Division" /employee: get: summary: Used to retrieve all employees. responses: 200: description: Return all employees from the database. content: application/json: schema: type: array items: "$ref": "#/components/schemas/Employee" components: schemas: Division: description: A part of a company. type: object x-tablename: division properties: id: type: integer description: Unique identifier for the division. example: 0 x-primary-key: true name: type: string description: The name of the division. example: Engineering. Employee: description: Person that works for a company. type: object x-tablename: employee properties: id: type: integer description: Unique identifier for the employee. example: 0 x-primary-key: true name: type: string description: The name of the employee. example: David Andersson division: allOf: - "$ref": "#/components/schemas/Division" - x-foreign-key-column: name |
The following file uses OpenAlchemy to generate the SQLAlchemy models:
1 2 3 4 5 6 | from open_alchemy import init_yaml init_yaml( "custom-foreign-key-example-spec.yml", models_filename="custom_foreign_key_models_auto.py", ) |
OpenAlchemy will generate the following typed models:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 | """Autogenerated SQLAlchemy models based on OpenAlchemy models.""" # pylint: disable=no-member,super-init-not-called,unused-argument import typing import sqlalchemy from sqlalchemy import orm from open_alchemy import models Base = models.Base # type: ignore class DivisionDict(typing.TypedDict, total=False): """TypedDict for properties that are not required.""" id: typing.Optional[int] name: typing.Optional[str] class TDivision(typing.Protocol): """ SQLAlchemy model protocol. A part of a company. Attrs: id: Unique identifier for the division. name: The name of the division. """ # SQLAlchemy properties __table__: sqlalchemy.Table __tablename__: str query: orm.Query # Model properties id: "sqlalchemy.Column[typing.Optional[int]]" name: "sqlalchemy.Column[typing.Optional[str]]" def __init__( self, id: typing.Optional[int] = None, name: typing.Optional[str] = None ) -> None: """ Construct. Args: id: Unique identifier for the division. name: The name of the division. """ ... @classmethod def from_dict( cls, id: typing.Optional[int] = None, name: typing.Optional[str] = None ) -> "TDivision": """ Construct from a dictionary (eg. a POST payload). Args: id: Unique identifier for the division. name: The name of the division. Returns: Model instance based on the dictionary. """ ... @classmethod def from_str(cls, value: str) -> "TDivision": """ Construct from a JSON string (eg. a POST payload). Returns: Model instance based on the JSON string. """ ... def to_dict(self) -> DivisionDict: """ Convert to a dictionary (eg. to send back for a GET request). Returns: Dictionary based on the model instance. """ ... def to_str(self) -> str: """ Convert to a JSON string (eg. to send back for a GET request). Returns: JSON string based on the model instance. """ ... Division: typing.Type[TDivision] = models.Division # type: ignore class EmployeeDict(typing.TypedDict, total=False): """TypedDict for properties that are not required.""" id: typing.Optional[int] name: typing.Optional[str] division: typing.Optional["DivisionDict"] class TEmployee(typing.Protocol): """ SQLAlchemy model protocol. Person that works for a company. Attrs: id: Unique identifier for the employee. name: The name of the employee. division: The division of the Employee. """ # SQLAlchemy properties __table__: sqlalchemy.Table __tablename__: str query: orm.Query # Model properties id: "sqlalchemy.Column[typing.Optional[int]]" name: "sqlalchemy.Column[typing.Optional[str]]" division: 'sqlalchemy.Column[typing.Optional["TDivision"]]' def __init__( self, id: typing.Optional[int] = None, name: typing.Optional[str] = None, division: typing.Optional["TDivision"] = None, ) -> None: """ Construct. Args: id: Unique identifier for the employee. name: The name of the employee. division: The division of the Employee. """ ... @classmethod def from_dict( cls, id: typing.Optional[int] = None, name: typing.Optional[str] = None, division: typing.Optional["DivisionDict"] = None, ) -> "TEmployee": """ Construct from a dictionary (eg. a POST payload). Args: id: Unique identifier for the employee. name: The name of the employee. division: The division of the Employee. Returns: Model instance based on the dictionary. """ ... @classmethod def from_str(cls, value: str) -> "TEmployee": """ Construct from a JSON string (eg. a POST payload). Returns: Model instance based on the JSON string. """ ... def to_dict(self) -> EmployeeDict: """ Convert to a dictionary (eg. to send back for a GET request). Returns: Dictionary based on the model instance. """ ... def to_str(self) -> str: """ Convert to a JSON string (eg. to send back for a GET request). Returns: JSON string based on the model instance. """ ... Employee: typing.Type[TEmployee] = models.Employee # type: ignore |
Relationship kwargs¶
There are a range of keyword arguments for the relationship in SQLAlchemy for a range of use cases. OpenAlchemy supports these using the x-kwargs extension property that can be defined along with an object or array reference.
See also
- Other Keyword Arguments
OpenAlchemy documentation for relationship keyword arguments.
- SQLAlchemy Relationship API
Documentation of the SQLAlchemy relationship API.
The following example defines the order_by keyword argument for the relationship between Employee and Division:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 | openapi: "3.0.0" info: title: Test Schema description: API to illustrate Many to One Relationships with keyword arguments. version: "0.1" paths: /division: get: summary: Used to retrieve all divisions. responses: 200: description: Return all divisions from the database. content: application/json: schema: type: array items: "$ref": "#/components/schemas/Division" /employee: get: summary: Used to retrieve all employees. responses: 200: description: Return all employees from the database. content: application/json: schema: type: array items: "$ref": "#/components/schemas/Employee" components: schemas: Division: description: A part of a company. type: object x-tablename: division properties: id: type: integer description: Unique identifier for the division. example: 0 x-primary-key: true name: type: string description: The name of the division. example: Engineering Employee: description: Person that works for a company. type: object x-tablename: employee properties: id: type: integer description: Unique identifier for the employee. example: 0 x-primary-key: true name: type: string description: The name of the employee. example: David Andersson division: allOf: - "$ref": "#/components/schemas/Division" - x-kwargs: order_by: Division.name |
The following file uses OpenAlchemy to generate the SQLAlchemy models:
1 2 3 | from open_alchemy import init_yaml init_yaml("kwargs-example-spec.yml", models_filename="kwargs_models_auto.py") |
The SQLAlchemy models generated by OpenAlchemy are equivalent to the following traditional models file:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 | import sqlalchemy as sa from sqlalchemy.ext.declarative import declarative_base Base = declarative_base() class Division(Base): """Division of a company.""" __tablename__ = "division" id = sa.Column(sa.Integer, primary_key=True) name = sa.Column(sa.String) class Employee(Base): """Person that works for a company.""" __tablename__ = "employee" id = sa.Column(sa.Integer, primary_key=True) name = sa.Column(sa.String) division = sa.orm.relationship("Division", order_by="Division.name") division_id = sa.Column(sa.Integer, sa.ForeignKey("division.id")) |
OpenAlchemy will generate the following typed models:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 | """Autogenerated SQLAlchemy models based on OpenAlchemy models.""" # pylint: disable=no-member,super-init-not-called,unused-argument import typing import sqlalchemy from sqlalchemy import orm from open_alchemy import models Base = models.Base # type: ignore class DivisionDict(typing.TypedDict, total=False): """TypedDict for properties that are not required.""" id: typing.Optional[int] name: typing.Optional[str] class TDivision(typing.Protocol): """ SQLAlchemy model protocol. A part of a company. Attrs: id: Unique identifier for the division. name: The name of the division. """ # SQLAlchemy properties __table__: sqlalchemy.Table __tablename__: str query: orm.Query # Model properties id: "sqlalchemy.Column[typing.Optional[int]]" name: "sqlalchemy.Column[typing.Optional[str]]" def __init__( self, id: typing.Optional[int] = None, name: typing.Optional[str] = None ) -> None: """ Construct. Args: id: Unique identifier for the division. name: The name of the division. """ ... @classmethod def from_dict( cls, id: typing.Optional[int] = None, name: typing.Optional[str] = None ) -> "TDivision": """ Construct from a dictionary (eg. a POST payload). Args: id: Unique identifier for the division. name: The name of the division. Returns: Model instance based on the dictionary. """ ... @classmethod def from_str(cls, value: str) -> "TDivision": """ Construct from a JSON string (eg. a POST payload). Returns: Model instance based on the JSON string. """ ... def to_dict(self) -> DivisionDict: """ Convert to a dictionary (eg. to send back for a GET request). Returns: Dictionary based on the model instance. """ ... def to_str(self) -> str: """ Convert to a JSON string (eg. to send back for a GET request). Returns: JSON string based on the model instance. """ ... Division: typing.Type[TDivision] = models.Division # type: ignore class EmployeeDict(typing.TypedDict, total=False): """TypedDict for properties that are not required.""" id: typing.Optional[int] name: typing.Optional[str] division: typing.Optional["DivisionDict"] class TEmployee(typing.Protocol): """ SQLAlchemy model protocol. Person that works for a company. Attrs: id: Unique identifier for the employee. name: The name of the employee. division: The division of the Employee. """ # SQLAlchemy properties __table__: sqlalchemy.Table __tablename__: str query: orm.Query # Model properties id: "sqlalchemy.Column[typing.Optional[int]]" name: "sqlalchemy.Column[typing.Optional[str]]" division: 'sqlalchemy.Column[typing.Optional["TDivision"]]' def __init__( self, id: typing.Optional[int] = None, name: typing.Optional[str] = None, division: typing.Optional["TDivision"] = None, ) -> None: """ Construct. Args: id: Unique identifier for the employee. name: The name of the employee. division: The division of the Employee. """ ... @classmethod def from_dict( cls, id: typing.Optional[int] = None, name: typing.Optional[str] = None, division: typing.Optional["DivisionDict"] = None, ) -> "TEmployee": """ Construct from a dictionary (eg. a POST payload). Args: id: Unique identifier for the employee. name: The name of the employee. division: The division of the Employee. Returns: Model instance based on the dictionary. """ ... @classmethod def from_str(cls, value: str) -> "TEmployee": """ Construct from a JSON string (eg. a POST payload). Returns: Model instance based on the JSON string. """ ... def to_dict(self) -> EmployeeDict: """ Convert to a dictionary (eg. to send back for a GET request). Returns: Dictionary based on the model instance. """ ... def to_str(self) -> str: """ Convert to a JSON string (eg. to send back for a GET request). Returns: JSON string based on the model instance. """ ... Employee: typing.Type[TEmployee] = models.Employee # type: ignore |