examples.performance.single_inserts — SQLAlchemy 2.0 Documentation

Release: 2.0.50 | Release Date: May 24, 2026

# SQLAlchemy 2.0 Documentation

# Source code for examples.performance.single_inserts

    """In this series of tests, we're looking at a method that inserts a row
    within a distinct transaction, and afterwards returns to essentially a
    "closed" state.   This would be analogous to an API call that starts up
    a database connection, inserts the row, commits and closes.

    """

    from sqlalchemy import bindparam
    from sqlalchemy import Column
    from sqlalchemy import create_engine
    from sqlalchemy import Identity
    from sqlalchemy import Integer
    from sqlalchemy import pool
    from sqlalchemy import String
    from sqlalchemy.ext.declarative import declarative_base
    from sqlalchemy.orm import Session
    from . import Profiler

    Base = declarative_base()
    engine = None

    class Customer(Base):
        __tablename__ = "customer"
        id = Column(Integer, Identity(), primary_key=True)
        name = Column(String(255))
        description = Column(String(255))

    Profiler.init("single_inserts", num=10000)

    @Profiler.setup
    def setup_database(dburl, echo, num):
        global engine
        engine = create_engine(dburl, echo=echo)
        if engine.dialect.name == "sqlite":
            engine.pool = pool.StaticPool(creator=engine.pool._creator)
        Base.metadata.drop_all(engine)
        Base.metadata.create_all(engine)

    @Profiler.profile
    def test_orm_commit(n):
        """Individual INSERT/COMMIT pairs via the ORM"""

        for i in range(n):
            session = Session(bind=engine)
            session.add(
                Customer(
                    name="customer name %d" % i,
                    description="customer description %d" % i,
                )
            )
            session.commit()

    @Profiler.profile
    def test_bulk_save(n):
        """Individual INSERT/COMMIT pairs using the "bulk" API"""

        for i in range(n):
            session = Session(bind=engine)
            session.bulk_save_objects(
                [
                    Customer(
                        name="customer name %d" % i,
                        description="customer description %d" % i,
                    )
                ]
            )
            session.commit()

    @Profiler.profile
    def test_bulk_insert_dictionaries(n):
        """Individual INSERT/COMMIT pairs using the "bulk" API with dictionaries"""

        for i in range(n):
            session = Session(bind=engine)
            session.bulk_insert_mappings(
                Customer,
                [
                    dict(
                        name="customer name %d" % i,
                        description="customer description %d" % i,
                    )
                ],
            )
            session.commit()

    @Profiler.profile
    def test_core(n):
        """Individual INSERT/COMMIT pairs using Core."""

        for i in range(n):
            with engine.begin() as conn:
                conn.execute(
                    Customer.__table__.insert(),
                    dict(
                        name="customer name %d" % i,
                        description="customer description %d" % i,
                    ),
                )

    @Profiler.profile
    def test_core_query_caching(n):
        """Individual INSERT/COMMIT pairs using Core with query caching"""

        cache = {}
        ins = Customer.__table__.insert()
        for i in range(n):
            with engine.begin() as conn:
                conn.execution_options(compiled_cache=cache).execute(
                    ins,
                    dict(
                        name="customer name %d" % i,
                        description="customer description %d" % i,
                    ),
                )

    @Profiler.profile
    def test_dbapi_raw_w_connect(n):
        """Individual INSERT/COMMIT pairs w/ DBAPI + connection each time"""

        _test_dbapi_raw(n, True)

    @Profiler.profile
    def test_dbapi_raw_w_pool(n):
        """Individual INSERT/COMMIT pairs w/ DBAPI + connection pool"""

        _test_dbapi_raw(n, False)

    def _test_dbapi_raw(n, connect):
        compiled = (
            Customer.__table__.insert()
            .values(name=bindparam("name"), description=bindparam("description"))
            .compile(dialect=engine.dialect)
        )

        if compiled.positional:
            args = (
                ("customer name %d" % i, "customer description %d" % i)
                for i in range(n)
            )
        else:
            args = (
                dict(
                    name="customer name %d" % i,
                    description="customer description %d" % i,
                )
                for i in range(n)
            )
        sql = str(compiled)

        if connect:
            for arg in args:
                # there's no connection pool, so if these were distinct
                # calls, we'd be connecting each time
                conn = engine.pool._creator()
                cursor = conn.cursor()
                cursor.execute(sql, arg)
                cursor.lastrowid
                conn.commit()
                conn.close()
        else:
            for arg in args:
                conn = engine.raw_connection()
                cursor = conn.cursor()
                cursor.execute(sql, arg)
                cursor.lastrowid
                conn.commit()
                conn.close()

    if __name__ == "__main__":
        Profiler.main()