asmysql v2 Changelog¶

This document records all changes in asmysql v2 version.

v2.1.0 ¶

Connection Init SQL (init_sql): Added init_sql parameter to automatically execute preset SQL on each new TCP connection's first use. Ideal for ClickHouse async insert configuration, MySQL session variable setup, and similar scenarios. Uses WeakKeyDictionary to track initialized connections. Fully backward compatible.

Auto-Commit Mechanism Refactored: Removed auto_commit Engine parameter and commit execute/Result parameter, replaced with SQL first-keyword-based auto-commit mechanism (_should_commit()). Write operations auto-COMMIT, read operations do not commit, stream mode does not commit
Removed Engine stream Parameter: stream is no longer an Engine class attribute, only available at execute() method level
Removed Engine result_class Parameter: result_class is no longer an Engine class attribute or constructor parameter, only available at the execute() / execute_many() method level, defaulting to tuple

Fixed 6 connection leak issues: fetch_all() custom type leak, double release after error, async for + break leak, non-MySQLError exception leak, __del__ crash, DDL/DML statements not releasing connections
Fixed 5 logic errors: echo_sql_log URL parsing, or operator overriding falsy values, concurrent race conditions, pool null passing, generic parameter semantic error
Fixed 5 medium/low-severity issues: release_connections() null check, @lru_cache memory leak, error_msg formatting, iterate() check inconsistency, property access crashes

Fixed non-existent API usage in homepage examples
Added init_sql documentation across connection.md, api.md, and examples.md (both Chinese and English versions)
Rewrote transaction control documentation to describe SQL statement type-based auto-commit mechanism
Fixed API documentation signatures: removed non-existent close/commit parameters

Added test_engine_init_sql.py covering init_sql core functionality and edge cases
Rewrote integration test engine fixture to auto-select test database via init_sql=USE <test_db>
Removed Engine result_class related test cases from test_mock_engine.py

v2.0.0 is a completely refactored version that is incompatible with v1. Main changes include:

Architecture Refactoring: Separated Engine and AsMysql classes, added independent Engine class to handle MySQL connections and execute statements
Result Class Changes: Result.err attribute renamed to Result.error
API Changes: Connection method changed from auto-connect to explicitly creating Engine and calling connect()

Engine Class: Brand new connection engine class with URL connection string support, connection status monitoring, and flexible connection management
Result Class Enhancements: Support for error information access (error_no, error_msg), streaming queries, context managers, async iterators, and custom result types
Execution Method Enhancements: execute() method supports stream, result_class parameters and multiple calling methods
Type Hints: Complete type hint support with generic types (Result[T])
Testing: New pytest test suite covering main functional scenarios

v2 version retains the core features of v1:

Easy to Use: asmysql is an easy-to-use library that wraps aiomysql
Connection Pool Management: Automatic MySQL connection pool management with reconnection mechanism
Error Handling: Global automatic capture of MysqlError errors
Separation of Execution and Retrieval: Separation of SQL statement execution and result retrieval
Type Hints: Complete Python type hint support
Business Logic Development: Directly inherit AsMysql class for logic development

For detailed migration guide, please refer to Migration Guide.