EnORM 1.0.1

EnORM—EnDATA Object Relational Mapper.

EnORM

EnORM—EnDATA Object Relational Mapper.

• EnORM
  • Example Usage
  • Documentation
    • API Reference
      • const .fkey.CASCADE [source]
      • class .column.Column(type_, length=None, rel=None, *, primary_key=False, default=None, nullable=True) [source]
      • class .types.Date [source]
      • class .types.DateTime [source]
      • class .db_engine.DBEngine(conn_str) [source]
      • class .db_session.DBSession(engine) [source]
      • class .fkey.ForeignKey(foreign_model, *, reverse_name, on_delete, on_update) [source]
      • class .model.Model(**attrs) [source]
      • class .types.Float [source]
      • class .types.Integer [source]
      • class .types.Serial [source]
      • class .types.String [source]
      • class .types.Time [source]
      • func agg(field, name_in_sql) -> .column.BaseColumn [source]
      • func count(field) -> .column.BaseColumn [source]
      • func sum_(field) -> .column.BaseColumn [source]
      • func avg(field) -> .column.BaseColumn [source]
      • func min_(field) -> .column.BaseColumn [source]
      • func max_(field) -> .column.BaseColumn [source]
      • func char_length(c) -> .column.Scalar [source]
      • func concat(*parts) -> str [source]
      • func current_date() -> .column.Scalar [source]
      • func current_time(precision=None) -> .column.Scalar [source]
      • func current_timestamp(precision=None) -> .column.Scalar [source]
      • func current_user() -> .column.Scalar [source]
      • func local_time(precision=None) -> .column.Scalar [source]
      • func local_timestamp() -> .column.Scalar [source]
      • func now() -> .column.Scalar [source]
      • func random() -> .column.Scalar [source]
      • func session_user() -> .column.Scalar [source]
      • func user() -> .column.Scalar [source]
    • Tutorial

Example Usage

from EnORM import CASCADE, Column, DBEngine, DBSession, Float, ForeignKey, Integer, Model, Serial, String


class Company(Model):
    __table__ = "companies"

    id = Column(Serial, primary_key=True)
    name = Column(String, nullable=False)
    country = Column(String, 40)


class Employee(Model):
    id = Column(Serial, primary_key=True)
    full_name = Column(String, 100, nullable=False)
    salary = Column(Float)
    age = Column(Integer)
    role = Column(String, 20, default="entry")
    company_id = Column(Serial, None, ForeignKey(Company, reverse_name="employees", on_delete=CASCADE))


eng = DBEngine("postgresql://user:secret@localhost:5432/my_db")

with DBSession(eng) as session:
    the_company = session.query(Company).filter(Company.country == "United Kingdom").first()

    new_employee = Employee(full_name="Nima Bavari Goudarzi", salary=64320.00, role="engineer", company_id=the_company.id)
    session.add(new_employee)
    
    sharks = session.query(Employee, Employee.full_name, Employee.company_id).filter(Employee.salary > 90000.00).all()

Documentation

API Reference

Reference for the EnORM public API.

const .fkey.CASCADE [source]

String literal "cascade".

class .column.Column(type_, length=None, rel=None, *, primary_key=False, default=None, nullable=True) [source]

Abstraction of a real table column in a database.

Parameters

type_ : typing.Type

The type of the column as represented in SQL.

length : int | None (default None)

Max length of the value. Provided only when the type of the column is .types.String.

rel : .fkey.ForeignKey | None (default None)

Marker of a relationship. Provided only when a foreign relation exists.

primary_key : bool (default False)

Whether or not the column is a primary key. Keyword-only.

default : typing.Any (default None)

Default value for cells of the column to take. Keyword-only.

nullable : bool (default True)

Whether or not the cells of the column are nullable. Keyword-only.

Attributes

model : typing.Type

Relational model that the column belongs to.

variable_name : str

Name with which the column is defined.

view_name : str

Name of the SQL table that the column belongs to.

class .types.Date [source]

ORM representation of datetime.date objects.

class .types.DateTime [source]

ORM representation of datetime.datetime objects.

class .db_engine.DBEngine(conn_str) [source]

Connection adapter for the .db_session.DBSession object.

Parameters

conn_str : str

Database resource location, along with auth params.

Attributes

conn : pyodbc.Connection

DB API connection object.

cursor : pyodbc.Cursor

DB API cursor object.

class .db_session.DBSession(engine) [source]

Singleton DB session to access the database across all uses.

Parameters

engine : .db_engine.AbstractEngine

DB engine that the session uses.

Attributes

engine : .db_engine.AbstractEngine

DB engine that the session uses.

queue : list

List of newly created instances of DB objects not yet persisted.

accumulator : list

List of ORM queries not yet executed.

Methods

query(*fields) -> .query.Query

Starts a query and returns the query object.

add(obj) -> None

Adds a new record to the DB session.

save() -> None

Persists all started queries.

commit_adds() -> None

Persists all added records on the DB session.

class .fkey.ForeignKey(foreign_model, *, reverse_name, on_delete, on_update) [source]

Representer of foreign key relations.

Parameters

foreign_model : typing.Type

MappedClass that represents a foreign model.

reverse_name : str

Relation name on the related class tied to this class. Keyword-only.

on_delete : str | None (default None)

Whether to delete cascade style or not. Keyword-only.

on_update : str | None (default None)

Whether to update cascade style or not. Keyword-only.

class .model.Model(**attrs) [source]

Abstract representer of an ORM database model in Python.

Parameters

attrs : typing.Any

Initialization attributes.

Attributes

sql : str

SQL statement for new object creation.

Methods

label(alias) -> .column.Label

Returns the ORM representation for SQL table aliasing.

class .types.Float [source]

ORM representation of float objects.

class .types.Integer [source]

ORM representation of int objects.

class .types.Serial [source]

ORM representation of serial types in SQL variants.

Parameters

val : int

Underlying integer value.

Attributes

val : int

Underlying integer value.

class .types.String [source]

ORM representation of str objects.

class .types.Time [source]

ORM representation of datetime.time objects.

func agg(field, name_in_sql) -> .column.BaseColumn [source]

Describes the basis for all aggregate functions.

Parameters

field : .column.BaseColumn

Argument.

name_in_sql : str

Name of the function in SQL.

func count(field) -> .column.BaseColumn [source]

Describes the SQL aggregate function COUNT.

func sum_(field) -> .column.BaseColumn [source]

Describes the SQL aggregate function SUM.

func avg(field) -> .column.BaseColumn [source]

Describes the SQL aggregate function AVG.

func min_(field) -> .column.BaseColumn [source]

Describes the SQL aggregate function MIN.

func max_(field) -> .column.BaseColumn [source]

Describes the SQL aggregate function MAX.

func char_length(c) -> .column.Scalar [source]

Describes the SQL function CHAR_LENGTH.

Parameters

c : .column.BaseColumn | str

Generic column or its string value.

func concat(*parts) -> str [source]

Concatenates multiple strings into one.

Parameters

parts : list of str

Separate parts.

func current_date() -> .column.Scalar [source]

Describes the SQL function CURRENT_DATE.

func current_time(precision=None) -> .column.Scalar [source]

Describes the SQL function CURRENT_TIME.

Parameters

precision : int | None (default None)

Number of significant decimal digits.

func current_timestamp(precision=None) -> .column.Scalar [source]

Describes the SQL function CURRENT_TIMESTAMP.

Parameters

precision : int | None (default None)

Number of significant decimal digits.

func current_user() -> .column.Scalar [source]

Describes the SQL function CURRENT_USER.

func local_time(precision=None) -> .column.Scalar [source]

Describes the SQL function LOCALTIME.

Parameters

precision : int | None (default None)

Number of significant decimal digits.

func local_timestamp() -> .column.Scalar [source]

Describes the SQL function LOCALTIMESTAMP.

func now() -> .column.Scalar [source]

Describes the SQL function NOW.

func random() -> .column.Scalar [source]

Describes the SQL function RANDOM.

func session_user() -> .column.Scalar [source]

Describes the SQL function SESSION_USER.

func user() -> .column.Scalar [source]

Describes the SQL function USER.

Tutorial