DSN flags

Every _* DSN flag mattn supported is translated transparently — usually into the equivalent PRAGMA. _strict=1 turns any unknown flag into an error (helpful during migration to flush typos out). The modern alternative to DSN strings is the typed sqlite.Config.

Flag (aliases)	Underlying action
_pragma=foo(1)	PRAGMA foo=1 (multi-value)
_foreign_keys / _fk	PRAGMA foreign_keys=
_busy_timeout / _timeout	PRAGMA busy_timeout=
_journal_mode / _journal	PRAGMA journal_mode=
_synchronous / _sync	PRAGMA synchronous=
_locking_mode / _locking	PRAGMA locking_mode=
_secure_delete	PRAGMA secure_delete=
_recursive_triggers / _rt	PRAGMA recursive_triggers=
_cache_size	PRAGMA cache_size=
_auto_vacuum / _vacuum	PRAGMA auto_vacuum=
_defer_foreign_keys / _defer_fk	PRAGMA defer_foreign_keys=
_ignore_check_constraints	PRAGMA ignore_check_constraints=
_case_sensitive_like / _cslike	PRAGMA case_sensitive_like=
_query_only	PRAGMA query_only=
_writable_schema	PRAGMA writable_schema=
_loc	aliased to _timezone (auto → Local)
_time_format, _time_integer_format, _inttotime, _texttotime, _timezone	inherited from modernc
_txlock	sets transaction begin mode
cache, mode, immutable, vfs	URI-level, passed through
_auth*	rejected — userauth was removed upstream
_strict=1	unknown flags become hard errors

For new code, prefer the typed sqlite.Config over a DSN string — it’s compile-checked and self-documenting. The common flags map to fields on Config.Pragmas (with typed enum values); anything without a dedicated field goes through Pragmas.Extra, which fires PRAGMA <key> = <value> exactly like _pragma=.

DSN flag	Typed field	Values
_journal / _journal_mode	Pragmas.JournalMode	JournalWAL · JournalDelete · JournalTruncate · JournalPersist · JournalMemory · JournalOff
_sync / _synchronous	Pragmas.Synchronous	SynchronousNormal · SynchronousOff · SynchronousFull · SynchronousExtra
_busy_timeout / _timeout	Pragmas.BusyTimeout	a time.Duration (mapped to ms)
_fk / _foreign_keys	Pragmas.ForeignKeys	true / false
_cache_size	Pragmas.CacheSize	pages (positive) or KiB (negative)
mode (URI)	Config.Mode	ModeReadWriteCreate · ModeReadWrite · ModeReadOnly · ModeMemory
cache (URI)	Config.Cache	CacheShared · CachePrivate
vfs (URI)	Config.VFS	a registered VFS name
any other _pragma=foo(v)	Pragmas.Extra	map[string]string → PRAGMA foo = v

Typed-only (no legacy DSN flag): Pragmas.TempStore (TempStoreMemory · TempStoreFile · TempStoreDefault) and Pragmas.AutoVacuum (AutoVacuumNone · AutoVacuumFull · AutoVacuumIncremental). Transparent at-rest encryption is opened via crypto.Open (the separate vfs/crypto module), not a DSN flag. Config.Pragmas is applied in struct-declaration order after open; RecommendedPragmas() is the production preset (WAL + busy_timeout=5s + foreign_keys=on). Full field semantics live in the Configuration guide and pkg.go.dev/gosqlite.org.