Release: 1.2.19 | Release Date: April 15, 2019

# SQLAlchemy 1.2 Documentation

# SQLAlchemy Documentation

## Getting Started

A high level view and getting set up.

Overview | Installation Guide | Frequently Asked Questions | Migration from 1.1 | Glossary | Error Messages | Changelog catalog

## SQLAlchemy ORM

Here, the Object Relational Mapper is introduced and fully described. If you want to work with higher-level SQL which is constructed automatically for you, as well as automated persistence of Python objects, proceed first to the tutorial.

- Read this first: Object Relational Tutorial

- ORM Configuration: Mapper Configuration | Relationship Configuration

- Configuration Extensions: Declarative Extension | Association Proxy | Hybrid Attributes | Automap | Mutable Scalars | Indexable

- ORM Usage: Session Usage and Guidelines | Loading Objects | Cached Query Extension

- Extending the ORM: ORM Events and Internals

- Other: Introduction to Examples

## SQLAlchemy Core

The breadth of SQLAlchemy’s SQL rendering engine, DBAPI integration, transaction integration, and schema description services are documented here. In contrast to the ORM’s domain-centric mode of usage, the SQL Expression Language provides a schema-centric usage paradigm.

- Read this first: SQL Expression Language Tutorial

- All the Built In SQL: SQL Expression API

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

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

- Datatypes: Overview | Building Custom Types | API

- 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 | SQLite | Oracle | Microsoft SQL Server

More Dialects …