sqlmodelgen

sqlmodelgen is a library to generate models for the sqlmodel library (repo, official docs).

It accepts in input the following sources:

• direct CREATE TABLE sql statements
• sqlite file path
• postgres connection string

Installation

Available on PyPi, just run pip install sqlmodelgen

Code generation from postgres requires the separate postgres extension, installable with pip install sqlmodelgen[postgres]

Usage

Generating from CREATE TABLE

from sqlmodelgen import gen_code_from_sql

sql_code = '''
CREATE TABLE Hero (
	id INTEGER NOT NULL, 
	name VARCHAR NOT NULL, 
	secret_name VARCHAR NOT NULL, 
	age INTEGER, 
	PRIMARY KEY (id)
);

print(gen_code_from_sql(sql_code))
'''

generates:

from sqlmodel import SQLModel, Field

class Hero(SQLModel, table = True):
    __tablename__ = 'Hero'
    id: int = Field(primary_key=True)
    name: str
    secret_name: str
    age: int | None

Generating from SQLite

from sqlmodelgen import gen_code_from_sqlite

code = gen_code_from_sqlite('/home/my_user/my_database.sqlite')

Generating from Postgres

The separate postgres extension is required, it can be installed with pip install sqlmodelgen[postgres].

from sqlmodelgen import gen_code_from_postgres

code = gen_code_from_postgres('postgres://USER:PASSWORD@HOST:PORT/DBNAME')

Relationships

sqlmodelgen allows to build relationships by passing the argument generate_relationships=True to the functions:

• gen_code_from_sql
• gen_code_from_sqlite
• gen_code_from_postgres

In such case sqlmodelgen is going to generate relationships between classes based on the foreign keys retrieved. The following example

schema = '''CREATE TABLE nations(
    id BIGSERIAL PRIMARY KEY,
    name TEXT NOT NULL
);

CREATE TABLE athletes(
    id BIGSERIAL PRIMARY KEY,
    name TEXT NOT NULL,
    nation_id BIGSERIAL,
    FOREIGN KEY (nation_id) REFERENCES nations(id)
);'''

sqlmodel_code = gen_code_from_sql(schema, generate_relationships=True)

will generate:

from sqlmodel import SQLModel, Field, Relationship

class Nations(SQLModel, table = True):
    __tablename__ = 'nations'

    id: int | None = Field(primary_key=True)
    name: str
    athletess: list['Athletes'] = Relationship(back_populates='nation')
                                                                             
class Athletes(SQLModel, table = True):
    __tablename__ = 'athletes'

    id: int | None = Field(primary_key=True)
    name: str
    nation_id: int | None = Field(foreign_key="nations.id")
    nation: Nations | None = Relationship(back_populates='athletess')

Internal functioning

The library relies on sqloxide to parse SQL code, then generates sqlmodel classes accordingly