pyxle-db 0.2.0

Changed (BREAKING)

• Database.transaction() now yields a transaction whose methods are
  coroutines: await tx.execute(...), await tx.fetchone(...), etc.
  In 0.1 these calls were synchronous inside the async context manager.
• Database.close() and Database.sync_transaction() are SQLite-only
  and raise UnsupportedOperationError on server backends. Use
  await db.aclose() and async with db.transaction() — both work on
  every backend.
• Mapping (named) parameters are SQLite-only; portable SQL uses
  positional ? parameters.

Added

• PostgreSQL backend via asyncpg (pip install 'pyxle-db[postgres]')
  and MySQL backend via asyncmy (pip install 'pyxle-db[mysql]').
  The base install remains SQLite-only with zero extra dependencies.

• Database URLs: Database(...)/connect(...) accept
  sqlite:///..., postgresql://..., and mysql://... connection
  strings alongside the 0.1 bare SQLite path. DatabaseConfig and
  parse_database_url are exported for programmatic use.

• Portable placeholders: qmark (?) SQL is translated per backend
  ($1 for PostgreSQL, %s for MySQL) with a literal-aware rewriter;
  ?? escapes a literal question mark for PostgreSQL JSON operators.

• Backend-neutral Row result type (index + name access) and Dialect
  metadata, both exported from pyxle_db.

• New error types: OperationalError (retryable connection/timeout
  family), ConfigurationError, and UnsupportedOperationError.
  Driver exceptions are translated on every backend — application code
  never handles sqlite3/asyncpg/asyncmy exceptions.

• Datetimes come back timezone-aware UTC on every backend; naive values
  stored in the database are assumed UTC and tagged.

• Plugin: new url setting that takes precedence over path, with
  env:VAR_NAME indirection so credentials stay out of the committed
  pyxle.config.json (startup raises ConfigurationError when the
  variable is unset). The plugin now also registers db.url, a
  password-redacted connection string for logging.

• Migrations: backend-specific override files
  (0003-fulltext-index.postgresql.sql next to
  0003-fulltext-index.sql) for migrations that need per-dialect DDL.

• DatabaseLike / TransactionLike protocols (pyxle_db.contract,
  exported at top level): the structural contract third-party database
  layers implement to back plugins like pyxle-auth. Database is the
  reference implementation; both protocols are runtime_checkable and
  the conformance is regression-tested.

Fixed

• Plugin shutdown awaits Database.aclose(), releasing async pools
  cleanly instead of relying on the SQLite-only synchronous close.
• Aware datetimes now bind on every backend (found by the live-server
  suites). PostgreSQL and MySQL pass parameters through
  utc_naive_params(): an aware datetime is converted to UTC and bound
  naive, matching the SQLite adapter and the read-side "naive equals
  UTC" rule. Previously asyncpg rejected aware datetimes for TIMESTAMP
  columns and asyncmy silently serialised the foreign wall clock.
• The MySQL pool pins each session to UTC (SET time_zone = '+00:00'),
  so TIMESTAMP columns and NOW() are no longer shifted through the
  server's system time zone on read.
• The mysql extra now includes cryptography: MySQL 8's default
  caching_sha2_password auth fails at connect without it.
• Dependency floor corrected to pyxle-framework>=0.4.0 — the
  pyxle.plugins API first shipped in 0.4.0, so older resolutions
  could not import.

Install: pip install pyxle-db · extras: [postgres], [mysql]
Docs: https://pyxle.dev/docs/plugins/pyxle-db