62 lines
1.8 KiB
Python
62 lines
1.8 KiB
Python
"""Async SQLAlchemy engine, session factory, and declarative base.
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Works with SQLite (aiosqlite) or Postgres (asyncpg) depending on DATABASE_URL.
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"""
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from collections.abc import AsyncGenerator
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from sqlalchemy import event
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from sqlalchemy.ext.asyncio import (
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AsyncSession,
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async_sessionmaker,
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create_async_engine,
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)
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from sqlalchemy.orm import DeclarativeBase
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from app.core.config import settings
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class Base(DeclarativeBase):
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"""Declarative base shared by all models."""
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engine = create_async_engine(settings.database_url, echo=settings.debug, future=True)
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if engine.sync_engine.dialect.name == "sqlite":
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@event.listens_for(engine.sync_engine, "connect")
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def _set_sqlite_pragma(dbapi_connection, connection_record) -> None:
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"""WAL mode lets readers/writers avoid blocking each other; busy_timeout
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makes a connection wait for a lock instead of immediately raising
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"database is locked" (the pysqlite/aiosqlite default is 0ms).
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"""
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cursor = dbapi_connection.cursor()
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cursor.execute("PRAGMA journal_mode=WAL")
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cursor.execute("PRAGMA busy_timeout=5000")
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cursor.close()
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AsyncSessionLocal = async_sessionmaker(
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engine,
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class_=AsyncSession,
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expire_on_commit=False,
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autoflush=False,
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)
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async def get_db() -> AsyncGenerator[AsyncSession, None]:
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"""FastAPI dependency yielding a request-scoped session."""
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async with AsyncSessionLocal() as session:
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yield session
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async def init_db() -> None:
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"""Create all tables. Convenient for dev/SQLite and tests.
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In production prefer Alembic migrations (``alembic upgrade head``).
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"""
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# Import models so they register with Base.metadata before create_all.
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import app.models # noqa: F401
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async with engine.begin() as conn:
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await conn.run_sync(Base.metadata.create_all)
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