[IlyaKhalafi]

Description

This PR fixes sql_mode= being ignored in MySQL database URLs. With this, an empty mode clears the default through both aiomysql and asyncmy.

Motivation and Context

Fixes #1311.

How Has This Been Tested?

make check, the full SQLite suite with 2,010 tests passing, and 101 focused tests with each driver. Real connections against MariaDB 10.11.14 also cover empty, default and explicit modes, transactions and reopening connections.

Checklist

• My code follows the code style of this project.
• I have added the changelog accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed in the environments listed above.

[codspeed]

Merging this PR will not alter performance

1 warning

⚠️ 21 benchmarks are dominated by system calls

System calls cannot be simulated consistently and are left out of the measure. The reported value understates the real cost. Switch to the Walltime instrument to measure them.

Learn more about system calls

See affected benchmarks

✅ 24 untouched benchmarks

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_{Comparing IlyaKhalafi:fix/empty-url-parameters (f40eb1b) with develop (abc91d7)}