SQLAlchemy is a Python SQL toolkit and a database object mapping framework. It includes a complete enterprise-class persistence model, specifically for efficient and high-performance database access.
SQL databases behave less like object collections the more size and performance start to matter; object collections behave less like tables and rows the more abstraction starts to matter. SQLAlchemy aims to accommodate both of these principles.
SQLAlchemy considers the database to be a relational algebra engine, not just a collection of tables. Rows can be selected from not only tables but also joins and other select statements; any of these units can be composed into a larger structure. SQLAlchemy’s expression language builds on this concept from its core.
SQLAlchemy is most famous for its object-relational mapper (ORM), an optional component that provides the data mapper pattern, where classes can be mapped to the database in open ended, multiple ways – allowing the object model and database schema to develop in a cleanly decoupled way from the beginning.
SQLAlchemy’s overall approach to these problems is entirely different from that of most other SQL / ORM tools, rooted in a so-called complimentarity- oriented approach; instead of hiding away SQL and object relational details behind a wall of automation, all processes are fully exposed within a series of composable, transparent tools. The library takes on the job of automating redundant tasks while the developer remains in control of how the database is organized and how SQL is constructed.
The main goal of SQLAlchemy is to change the way you think about databases and SQL!
SQLAlchemy 1.3.1 has been released, this release contains various fixes.
[orm] [bug] [ext] Fixed regression where an association proxy linked to a synonym would no longer work, both at instance level and at class level.
[mssql] [bug] A commit() is emitted after an isolation level change to SNAPSHOT, as both pyodbc and pymssql open an implicit transaction which blocks subsequent SQL from being emitted in the current transaction.
This change is also backported to: 1.2.19
[mssql] [bug] Fixed regression in SQL Server reflection due to #4393 where the removal of open-ended
Floatdatatype caused reflection of this type to fail due to a “scale” argument being passed.