![]() Database introspection and generation.Surrogate integer primary keys are of course still the norm, but SQLAlchemy never assumes or hardcodes to this model. All primary and foreign key constraints are assumed to be composite and natural.The SQLAlchemy Core is separate from the ORM and is a full database abstraction layer in its own right, and includes an extensible Python-based SQL expression language, schema metadata, connection pooling, type coercion, and custom types. A Core SQL construction system and a DBAPI interaction layer.Collections are cached within a session and can be loaded on individual access, all at once using joins, or by query per collection across the full result set. A comprehensive and flexible system of eager loading for related collections and objects.While you can drop into literal SQL at any time, it’s virtually never needed. Writing queries with the ORM uses the same techniques of relational composition you use when writing SQL. A relationally-oriented query system, exposing the full range of SQL’s capabilities explicitly, including joins, subqueries, correlation, and most everything else, in terms of the object model.Domain models can be constructed and manipulated naturally, and changes are synchronized with the current transaction automatically. These patterns allow the transparent persistence of objects using a declarative configuration system. ![]()
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