sqlalchemy/sqlalchemy

Features

• Object-Relational Mapping - Maps Python classes to relational database tables using declarative or imperative styles for object-oriented data persistence.
• Asynchronous SQL Toolkits - Provides a comprehensive library for interacting with relational databases using object-oriented patterns and a powerful SQL expression language.
• SQL Query Builders - Provides a programmatic interface for constructing complex, dialect-agnostic SQL queries using composable objects.
• Object-Relational Mappers - Maps database tables to Python classes, enabling developers to manage data persistence through object state and relationships.
• Common Table Expressions - Constructs recursive or non-recursive temporary result sets to organize complex queries into modular, reusable components.
• Data Modification Interfaces - Performs insert, update, and delete operations on database records using a unified interface that abstracts underlying SQL syntax.
• Database Schema Constraints - Enforces data integrity rules such as primary keys, foreign keys, unique values, and custom check expressions.
• Database Transaction Management - Manages atomic units of work across multiple operations, supporting savepoints, two-phase commits, and configurable isolation levels.
• Object-Relational Mapping Associations - Links multiple related entities or subqueries using relationship-aware syntax to retrieve associated data across relational boundaries.
• State Change Tracking - Monitors modifications to object attributes and collections to ensure that changes are detected and persisted correctly.
• Schema Generation Utilities - Automates the generation and application of database schema definitions directly from object models to initialize or update structures.
• Asynchronous Session Managers - Provides a stateful session interface for database operations that supports awaitable execution and transaction management within asynchronous workflows.
• Custom SQL Function Registrars - Provides a registration interface for custom or vendor-specific SQL functions to ensure consistent usage within the query builder.
• Database Model Mixins - SQLAlchemy shares common columns, constraints, and behaviors across multiple models using mixins and abstract base classes.
• State Persistence - Tracks object state changes within a session to coordinate atomic database transactions and minimize redundant write operations.
• Hybrid Attributes - Creates class attributes that behave as both properties and SQL expressions to allow consistent logic across application code and queries.
• Database Clients - Database toolkit for Python.
• Database ORMs - Listed in the “Database ORMs” section of the Awesome Python awesome list.
• Database Tools - SQL toolkit and ORM for Python.
• Object Relational Mappers - SQL toolkit and object relational mapper.
• Persistence Frameworks - Comprehensive SQL toolkit and ORM for Python.
• Asynchronous Database Command Execution - Performs database operations using non-blocking input and output to handle multiple concurrent requests without stalling the application event loop.
• Asynchronous Database Drivers - Provides a unified layer for performing non-blocking database operations and managing transactions within asynchronous Python environments.
• Bulk Data Operations - Performs high-performance insert, update, and delete operations on multiple records simultaneously while maintaining mapping consistency.
• Column Expression Modifiers - Allows refining query results by adding ordering, labeling, or filtering clauses to column expressions during statement construction.
• Data Sharding - Routes database queries and operations to specific physical nodes based on defined partitioning logic to scale storage capacity.
• Database Driver Abstractions - Provides a unified interface for database communication by abstracting vendor-specific behaviors into modular driver implementations.
• Table Metadata Inspection - Retrieves metadata about database structures such as tables and columns, including support for asynchronous inspection.
• Inheritance Mappings - Supports single-table, joined-table, and concrete-table inheritance strategies to represent object-oriented hierarchies in relational databases.
• Relation Loading Strategies - Controls how and when related data is fetched, including options for eager loading, lazy loading, and write-only access patterns.
• Database Value Generation - Configures columns to use database-native identity or sequence objects to automatically generate unique identifiers.
• Database Schema Reflection - SQLAlchemy allows modifying column definitions or properties during the process of reading database metadata for table reflection.
• Column Definitions - Assigns scalar values, functions, or SQL expressions to columns to automatically populate data during insert or update operations.
• Data Type Mappings - Provides native mapping for database-specific types including JSON, arrays, and range types for advanced data modeling.
• Data Upsert Operations - Performs insert-or-update logic using database-native duplicate key update syntax to handle conflicting records.
• Database Connection Managers - Maintains and reuses persistent database connections to optimize performance and resource usage in concurrent applications.
• Connection Pool Managers - Maintains a pool of persistent database connections to optimize performance and ensure stable resource usage.
• Schema Modification - Provides programmatic constructs for creating and modifying standard SQL schema objects like tables.
• Database Relationship Mappings - Models tree-like structures using adjacency lists, materialized paths, or nested sets to persist and query parent-child relationships.
• Eager Loading Strategies - Configures how subclasses are retrieved and loaded when querying base classes, including eager loading and subtype filtering.
• Expression-Based Data Querying - Translates high-level programming objects into vendor-specific SQL strings by traversing a tree of composable expression constructs.
• Polymorphic Associations - Associates multiple parent types with a single child object using polymorphic discriminators or flexible foreign key patterns.
• Compilation Caches - Stores and reuses compiled SQL statement strings to reduce computational overhead and speed up query execution.
• SQL Dialect Adapters - Provides specialized compilation rules for different database backends to ensure custom SQL constructs render correctly across engines.
• Transaction Control Systems - Configures transaction isolation levels and characteristics to control data consistency and concurrency behavior.
• Table Function Invocation - Maps database functions that return sets of rows directly to queryable table aliases within SQL statements.
• Value Objects - Encapsulates data and associated comparison logic into objects that behave consistently across Python and SQL contexts.
• Custom Data Types - Extends the type system by creating user-defined types to handle specialized data serialization, validation, or database-specific operator logic.
• Query Result Caching - Stores and retrieves query results or lazy-loaded attributes in external backends to reduce redundant database load.
• Metadata-Driven Schema Mappers - Inspects existing database structures at runtime to automatically generate application-level models and mapping configurations.
• Database Alias Management - Creates named aliases for tables or subqueries to manage namespace conflicts and simplify complex query structures.
• Database Lifecycle Hooks - Allows custom logic to be injected into the query and persistence pipeline by triggering callbacks during specific database operations.
• Partitioning Implementations - Declares partitioned tables using strategies like RANGE, LIST, or HASH to distribute data across multiple physical storage segments.
• Object-Relational Mapping Utilities - Propagates state changes like deletions, merges, and refreshes automatically across related objects based on defined relationship rules.
• Attribute Proxies - Exposes attributes from related objects or collections directly on a parent object to simplify data access.
• Query Execution Triggers - Provides hooks into the query lifecycle to apply global filters, custom criteria, or caching logic automatically.
• Result Streaming APIs - Supports incremental data retrieval using server-side cursors to process large result sets efficiently without exhausting application memory.
• Database Indexes - Speeds up data retrieval by defining single-column, composite, or functional indexes that allow the database to locate specific records.
• Dynamic Invocation Interfaces - Enables flexible SQL generation by invoking database functions through dynamic namespaces with type-safe return values.
• Logical Operations - Combines multiple filter conditions using AND, OR, and NOT logic to construct complex database query criteria.
• Relational Value Comparisons - Evaluates relationships between database columns and values using standard comparison operators like equality and range checks.
• Entity Audit Logs - Maintains historical records of object changes by automatically creating audit logs or using temporal row versioning.
• Asynchronous Execution - Enables non-blocking database operations by wrapping them within an event loop for asynchronous application environments.

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