SQLAlchemy Documentation — SQLAlchemy 2.0 Documentation

Release: 2.0.42 | Release Date: July 29, 2025

# SQLAlchemy 2.0 Documentation

# SQLAlchemy Documentation

Getting Started

New to SQLAlchemy? Start here:

- For Python Beginners: Installation Guide - basic guidance on installing with pip and similar

- For Python Veterans: SQLAlchemy Overview - brief architectural overview

Tutorials

New users of SQLAlchemy, as well as veterans of older SQLAlchemy release series, should start with the SQLAlchemy Unified Tutorial, which covers everything an Alchemist needs to know when using the ORM or just Core.

- For a quick glance: ORM Quick Start - a glimpse at what working with the ORM looks like

- For all users: SQLAlchemy Unified Tutorial - In depth tutorial for Core and ORM

Migration Notes

Users coming from older versions of SQLAlchemy, especially those transitioning from the 1.x style of working, will want to review this documentation.

- Migrating to SQLAlchemy 2.0 - Complete background on migrating from 1.3 or 1.4 to 2.0

- What’s New in SQLAlchemy 2.0? - New 2.0 features and behaviors beyond the 1.x migration

- Changelog catalog - Detailed changelogs for all SQLAlchemy Versions

Reference and How To

SQLAlchemy ORM - Detailed guides and API reference for using the ORM

- Mapping Classes: Mapping Python Classes | Relationship Configuration

- Using the ORM: Using the ORM Session | ORM Querying Guide | Using AsyncIO

- Configuration Extensions: Association Proxy | Hybrid Attributes | Mutable Scalars | Automap | All extensions

- Extending the ORM: ORM Events and Internals

- Other: Introduction to Examples

SQLAlchemy Core - Detailed guides and API reference for working with Core

- Engines, Connections, Pools: Engine Configuration | Connections, Transactions, Results | AsyncIO Support | Connection Pooling

- Schema Definition: Overview | Tables and Columns | Database Introspection (Reflection) | Insert/Update Defaults | Constraints and Indexes | Using Data Definition Language (DDL)

- SQL Statements: SQL Expression Elements | Operator Reference | SELECT and related constructs | INSERT, UPDATE, DELETE | SQL Functions | Table of Contents

- Datatypes: Overview | Building Custom Types | Type API Reference

- Core Basics: Overview | Runtime Inspection API | Event System | Core Event Interfaces | Creating Custom SQL Constructs

Dialect Documentation

The dialect is the system SQLAlchemy uses to communicate with various types of DBAPIs and databases. This section describes notes, options, and usage patterns regarding individual dialects.

PostgreSQL | MySQL and MariaDB | SQLite | Oracle Database | Microsoft SQL Server

More Dialects …

Supplementary

- Frequently Asked Questions - A collection of common problems and solutions

- Glossary - Definitions of terms used in SQLAlchemy documentation

- Error Message Guide - Explanations of many SQLAlchemy errors

- Complete table of of contents - Full list of available documentation

- Index - Index for easy lookup of documentation topics