sqlalchemy.engine Engine Example Code

Engine is a class within the sqlalchemy.engine module of the SQLAlchemy project.

Connection, create_engine, default, and url are several other callables with code examples from the same sqlalchemy.engine package.

Example 1 from CTFd

CTFd (homepage) is a capture the flag (CTF) hacking web app built with SQLAlchemy and Flask. The application can be used as-is to run CTF events, or the code can be modified for custom rules on hacking scenarios. CTFd is open sourced under the Apache License 2.0.

CTFd / CTFd / init.py

# __init__.py
import datetime
import os
import sys
import weakref
from distutils.version import StrictVersion

import jinja2
from flask import Flask, Request
from flask_migrate import upgrade
from jinja2 import FileSystemLoader
from jinja2.sandbox import SandboxedEnvironment
from werkzeug.middleware.proxy_fix import ProxyFix
from werkzeug.utils import cached_property

from CTFd import utils
from CTFd.plugins import init_plugins
from CTFd.utils.crypto import sha256
from CTFd.utils.initialization import (
    init_events,
    init_logs,
    init_request_processors,
    init_template_filters,
    init_template_globals,
)
from CTFd.utils.migrations import create_database, migrations, stamp_latest_revision
from CTFd.utils.sessions import CachingSessionInterface
from CTFd.utils.updates import update_check

__version__ = "3.0.0b2"


class CTFdRequest(Request):
    @cached_property
    def path(self):
        return self.script_root + super(CTFdRequest, self).path


## ... source file abbreviated to get to Engine examples ...


            }
        )
        app.jinja_loader = jinja2.ChoiceLoader([app.theme_loader, app.plugin_loader])

        from CTFd.models import (  # noqa: F401
            db,
            Teams,
            Solves,
            Challenges,
            Fails,
            Flags,
            Tags,
            Files,
            Tracking,
        )

        url = create_database()

        app.config["SQLALCHEMY_DATABASE_URI"] = str(url)

        db.init_app(app)

        migrations.init_app(app, db)

        if url.drivername.startswith("sqlite"):
            from sqlalchemy.engine import Engine
            from sqlalchemy import event

            @event.listens_for(Engine, "connect")
            def set_sqlite_pragma(dbapi_connection, connection_record):
                cursor = dbapi_connection.cursor()
                cursor.execute("PRAGMA foreign_keys=ON")
                cursor.close()

            db.create_all()
            stamp_latest_revision()
        else:
            upgrade()

        from CTFd.models import ma

        ma.init_app(app)

        app.db = db
        app.VERSION = __version__

        from CTFd.cache import cache

        cache.init_app(app)
        app.cache = cache

        reverse_proxy = app.config.get("REVERSE_PROXY")
        if reverse_proxy:


## ... source file continues with no further Engine examples...

Example 2 from GINO

GINO (project documentation and PyPI package information) is an object-relational mapper (ORM) built on SQLAlchemy that is non-blocking and therefore designed to work properly with asynchronously-run code, for example, an application written with asyncio.

GINO is open sourced under the BSD License.

GINO / src/gino / engine.py

# engine.py
import asyncio
import collections
import functools
import sys
import time
from contextvars import ContextVar

from sqlalchemy.cutils import _distill_params
from sqlalchemy.engine import Engine, Connection
from sqlalchemy.sql import schema

from .aiocontextvars import patch_asyncio
from .exceptions import MultipleResultsFound, NoResultFound
from .transaction import GinoTransaction

patch_asyncio()


class _BaseDBAPIConnection:
    _reset_agent = None
    gino_conn = None

    def __init__(self, cursor_cls):
        self._cursor_cls = cursor_cls
        self._closed = False

    def commit(self):
        pass

    def cursor(self):
        return self._cursor_cls(self)

    @property


## ... source file abbreviated to get to Engine examples ...


        return super()._execute_context(
            dialect, constructor, statement, parameters, *args
        )

    def _execute_baked_query(self, bq, multiparams, params):
        elem = bq.query
        if self._has_events or self.engine._has_events:
            for fn in self.dispatch.before_execute:
                _, multiparams, params = fn(self, elem, multiparams, params)

        distilled_params = _distill_params(multiparams, params)

        ret = self._execute_context(
            self.dialect,
            self.dialect.execution_ctx_cls._init_baked_query,
            bq.compiled_sql,
            distilled_params,
            bq,
            distilled_params,
        )
        if self._has_events or self.engine._has_events:
            self.dispatch.after_execute(self, elem, multiparams, params, ret)
        return ret


class _SAEngine(Engine):
    _connection_cls = _SAConnection

    def __init__(self, dialect, **kwargs):
        super().__init__(None, dialect, None, **kwargs)


class _AcquireContext:
    __slots__ = ["_acquire", "_conn"]

    def __init__(self, acquire):
        self._acquire = acquire
        self._conn = None

    async def __aenter__(self):
        self._conn = await self._acquire()
        return self._conn

    async def __aexit__(self, exc_type, exc_val, exc_tb):
        conn, self._conn = self._conn, None
        await conn.release()

    def __await__(self):
        return self._acquire().__await__()



## ... source file continues with no further Engine examples...
1. Introduction 2. Development Environments 3. Data 4. Web Development 5. Deployment 6. DevOps Changelog What Full Stack Means About the Author Future Directions Page Statuses SQLAlchemy ExtensionsSQLAlchemy Example CodeSQLAlchemy Modelssqlalchemy.databases mysqlsqlalchemy.dialects mssqlsqlalchemy.dialects mysqlsqlalchemy.dialects oraclesqlalchemy.schema DDLsqlalchemy.dialects postgresqlsqlalchemy.sql.expression Functionsqlalchemy.dialects sqlitesqlalchemy.dialects.mysql pymysqlsqlalchemy.dialects.postgresql ARRAYsqlalchemy.dialects.postgresql BIGINTsqlalchemy.dialects.postgresql BITsqlalchemy.dialects.postgresql DOUBLE_PRECISIONsqlalchemy.dialects.postgresql ExcludeConstraintsqlalchemy.dialects.postgresql INTEGERsqlalchemy.dialects.postgresql JSONsqlalchemy.dialects.postgresql TSVECTORsqlalchemy.dialects.postgresql pypostgresqlsqlalchemy.dialects.postgresql.base PGCompilersqlalchemy.dialects.postgresql.base PGIdentifierPreparersqlalchemy.dialects.postgresql.base PGTypeCompilersqlalchemy.dialects.postgresql.psycopg2 PGDialect_psycopg2sqlalchemy.dialects.sqlite pysqlitesqlalchemy.engine Connectionsqlalchemy.engine Enginesqlalchemy.engine create_enginesqlalchemy.engine defaultsqlalchemy.engine urlsqlalchemy.engine.default DefaultDialectsqlalchemy.engine.interfaces ExecutionContextsqlalchemy.engine.result ResultMetaDatasqlalchemy.engine.result RowProxysqlalchemy.engine.strategies EngineStrategysqlalchemy.engine.strategies MockEngineStrategysqlalchemy.engine.url make_urlsqlalchemy.events SchemaEventTargetsqlalchemy.exc ArgumentErrorsqlalchemy.exc DataErrorsqlalchemy.exc DatabaseErrorsqlalchemy.exc IntegrityErrorsqlalchemy.exc InvalidRequestErrorsqlalchemy.exc NoInspectionAvailablesqlalchemy.exc NoSuchTableErrorsqlalchemy.exc OperationalErrorsqlalchemy.exc ProgrammingErrorsqlalchemy.exc UnsupportedCompilationErrorsqlalchemy.ext compilersqlalchemy.ext.associationproxy AssociationProxysqlalchemy.ext.automap automap_basesqlalchemy.ext.compiler compilessqlalchemy.ext.declarative DeclarativeMetasqlalchemy.ext.declarative declarative_basesqlalchemy.ext.hybrid hybrid_methodsqlalchemy.ext.hybrid hybrid_propertysqlalchemy.ext.mutable Mutablesqlalchemy.inspection inspectsqlalchemy.orm ColumnPropertysqlalchemy.orm CompositePropertysqlalchemy.orm Loadsqlalchemy.orm Querysqlalchemy.orm RelationshipPropertysqlalchemy.orm SynonymPropertysqlalchemy.orm aliasedsqlalchemy.orm attributessqlalchemy.orm backrefsqlalchemy.orm class_mappersqlalchemy.orm column_propertysqlalchemy.orm compositesqlalchemy.orm interfacessqlalchemy.orm mappersqlalchemy.orm mapperlibsqlalchemy.orm object_mappersqlalchemy.orm object_sessionsqlalchemy.orm relationshipsqlalchemy.orm sessionsqlalchemy.orm sessionmakersqlalchemy.orm strategiessqlalchemy.orm.attributes InstrumentedAttributesqlalchemy.orm.attributes QueryableAttributesqlalchemy.orm.attributes flag_modifiedsqlalchemy.orm.collections InstrumentedListsqlalchemy.orm.exc NoResultFoundsqlalchemy.orm.exc UnmappedClassErrorsqlalchemy.orm.exc UnmappedInstanceErrorsqlalchemy.orm.interfaces MapperPropertysqlalchemy.orm.interfaces PropComparatorsqlalchemy.orm.mapper Mappersqlalchemy.orm.properties ColumnPropertysqlalchemy.orm.properties RelationshipPropertysqlalchemy.orm.query Querysqlalchemy.orm.query QueryContextsqlalchemy.orm.relationships RelationshipPropertysqlalchemy.orm.session Sessionsqlalchemy.orm.session object_sessionsqlalchemy.orm.util AliasedClasssqlalchemy.orm.util AliasedInspsqlalchemy.orm.util identity_keysqlalchemy.pool NullPoolsqlalchemy.pool StaticPoolsqlalchemy.schema CheckConstraintsqlalchemy.schema Columnsqlalchemy.schema CreateIndexsqlalchemy.schema CreateTablesqlalchemy.schema DDLElementsqlalchemy.schema ForeignKeysqlalchemy.schema ForeignKeyConstraintsqlalchemy.schema Indexsqlalchemy.schema PrimaryKeyConstraintsqlalchemy.schema Tablesqlalchemy.sql ClauseElementsqlalchemy.sql columnsqlalchemy.sql expressionsqlalchemy.sql extractsqlalchemy.sql functionssqlalchemy.sql operatorssqlalchemy.sql schemasqlalchemy.sql selectsqlalchemy.sql sqltypessqlalchemy.sql tablesqlalchemy.sql.compiler SQLCompilersqlalchemy.sql.elements ColumnElementsqlalchemy.sql.elements Labelsqlalchemy.sql.expression ClauseElementsqlalchemy.sql.expression ColumnClausesqlalchemy.sql.expression ColumnElementsqlalchemy.sql.expression Executablesqlalchemy.sql.expression FunctionElementsqlalchemy.sql.expression UnaryExpressionsqlalchemy.sql.functions FunctionElementsqlalchemy.sql.functions GenericFunctionsqlalchemy.sql.naming convsqlalchemy.sql.schema Columnsqlalchemy.sql.schema SchemaItemsqlalchemy.sql.sqltypes NullTypesqlalchemy.sql.util ClauseAdaptersqlalchemy.sql.visitors traversesqlalchemy.types Booleansqlalchemy.types Datesqlalchemy.types DateTimesqlalchemy.types Enumsqlalchemy.types Floatsqlalchemy.types Integersqlalchemy.types Intervalsqlalchemy.types NULLTYPEsqlalchemy.types Stringsqlalchemy.types Textsqlalchemy.types Timesqlalchemy.types TypeEnginesqlalchemy.types UserDefinedTypesqlalchemy.types to_instancesqlalchemy.util OrderedDictsqlalchemy.util OrderedSetsqlalchemy.util set_creation_ordersqlalchemy.util symbolsqlalchemy.util topologicalsqlalchemy.util.langhelpers public_factorysqlalchemy.util.langhelpers symbol ...or view the full table of contents.

Full Stack Python

Full Stack Python is an open book that explains concepts in plain language and provides helpful resources for those topics.
Updates via Twitter & Facebook.

Matt Makai 2012-2022