Fixed

• Added support for libsqlite3-sys 0.37.0
• Raise a compile-time error when mixing aggregate and non-aggregate expressions in an ORDER BY clause without a GROUP BY clause
• Calling .count() or .select(aggregate_expr) on a query that already has a non-aggregate .order_by() clause now raises a compile-time error instead of generating invalid SQL that would be rejected by the database at runtime (fixes #3815)
• Added documentation for migration transaction behaviour at the crate root
• Improved compile time error messages for #[derive(AsChangeset)]
• Allow to use generic types in infix_operator!()
• Fixes for several instances of unsound, unspecified or otherwise dangerous behaviour:
  • Unsound string construction in SqliteValue::read_text/FromSql<Text, Sqlite> for String
  • Invalid alignment for over aligned data in SqliteConnection::register_function for aggregate functions
  • Potential memory leaks in SqliteConnection::register_function
  • Access to padding bytes while serializing Date/time types in the Mysql backend
  • SQL Option Injection in PostgreSQL COPY FROM/TO
  • Unspecified pointer cast in Debug/Display implementation of batch INSERT statements for SQLite
  • Invalid call order of SQLite API functions in SqliteValue::read_text/FromSql<Text, Sqlite> for String/SqliteValue::read_blob()/FromSql<Binary, Sqlite> for Vec<u8>
  • Potential unsound pointer access for FromSql<Binary, _> for Vec<u8> and FromSql<Text, _> for String for third party backends (requires changes to the third party backend as well)

You can support the development of Diesel by:

• Contributing Code, Documentation or Guides. Checkout the planing for Diesel 2.4 for open tasks.
• Providing knowledge and help to maintain the MySQL/MariaDB backend. This is currently the only in-tree backend that is not used by any maintainers, so having someone around that actually uses this backend would be very helpful for the Diesel project.
• Answering questions in our discussion forum
• Reporting bugs in our issue tracker
• Helping triaging issues in our issue tracker
• Sponsoring the maintainers.

Full Changelog: https://github.com/diesel-rs/diesel/compare/v2.3.7...v2.3.8