PDO compatibility

$this->db()->pdo() runs queries against the Atom’s SQLite database through the Cloudflare runtime. It supports part of the native PDO API; unsupported operations throw PDOException.

The compatibility matrix records tests that run the same operations against Atoms and native pdo_sqlite. Use it to check individual methods and fetch modes.

Status vocabulary

Status	Meaning
Supported	Result matches native pdo_sqlite.
Refused	Atoms throws a typed PDOException where native PDO answers.
Refused by both	Both drivers reject the operation, with differences recorded.
Differs	Both answer but a measured bridge or language-boundary difference remains.
Undefined	PDO itself does not define a portable result.

Important differences

• SQLite extension callbacks such as sqliteCreateFunction(), aggregates, and collations are permanently unavailable: PHP callbacks cannot run inside the Durable Object SQL engine.
• getAttribute(PDO::ATTR_SERVER_VERSION) and getAttribute(PDO::ATTR_CLIENT_VERSION) throw: the PHP runtime and Durable Object use different SQLite builds.
• Give each result column a unique name. Duplicate names lose information when query results cross from SQLite into PHP; this also affects positional and grouping fetch modes.
• Whole-number REAL values can cross back as PHP integers because workerd exposes INTEGER and REAL through the same JavaScript number type.
• Wide INTEGER results must be selected with CAST(column AS TEXT) to preserve values above JavaScript’s safe integer range.
• prepare() accepts an empty options array or [PDO::ATTR_CURSOR => PDO::CURSOR_FWDONLY]. Other options throw.

For example, alias both id columns in a join:

SELECT players.id AS player_id, teams.id AS team_id
FROM players JOIN teams ON teams.id = players.team_id;