Struct Connection 

pub struct Connection { /* private fields */ }

Wraps the duckdb_connection and duckdb_database provided to your extension at load time.

Connection implements Registrar, offering a single, uniform API for registering all extension components. It also exposes register_replacement_scan and register_replacement_scan_with_data, which require the duckdb_database handle and therefore cannot be part of the Registrar trait.

Obtaining a Connection

Use init_extension_v2 (or the entry_point_v2! macro). Both pass a &Connection to your registration callback.

Version compatibility

Connection provides a uniform API across DuckDB 1.4.x and 1.5.x. When future DuckDB releases add new C API surface, additional methods will be gated on the corresponding feature flag.

Implementations

impl Connection

pub const fn as_raw_connection(&self) -> duckdb_connection

Return the raw duckdb_connection handle.

Use this to call C API functions that quack-rs does not yet wrap.

pub const fn as_raw_database(&self) -> duckdb_database

Return the raw duckdb_database handle.

Use this to call C API functions that require the database handle, such as replacement scan registration or (with duckdb-1-5) config option registration.

pub unsafe fn register_replacement_scan( &self, callback: ReplacementScanFn, extra_data: *mut c_void, delete_callback: duckdb_delete_callback_t, )

Register a replacement scan backed by a raw function pointer and extra data.

For the ergonomic owned-data variant, see register_replacement_scan_with_data.

Safety

• The underlying duckdb_database must be valid.
• extra_data must remain valid until delete_callback is called (or until the database is closed if delete_callback is None).

pub unsafe fn register_replacement_scan_with_data<T: 'static>( &self, callback: ReplacementScanFn, data: T, )

Register a replacement scan with owned extra data.

Boxes data and registers a drop destructor automatically. This is the safe, ergonomic alternative to register_replacement_scan.

Safety

The underlying duckdb_database must be valid.

Trait Implementations

impl Registrar for Connection

unsafe fn register_scalar( &self, builder: ScalarFunctionBuilder, ) -> Result<(), ExtensionError>

Register a scalar function.

unsafe fn register_scalar_set( &self, builder: ScalarFunctionSetBuilder, ) -> Result<(), ExtensionError>

Register a scalar function set (multiple overloads under one name).

unsafe fn register_aggregate( &self, builder: AggregateFunctionBuilder, ) -> Result<(), ExtensionError>

Register an aggregate function.

unsafe fn register_aggregate_set( &self, builder: AggregateFunctionSetBuilder, ) -> Result<(), ExtensionError>

Register an aggregate function set (multiple overloads under one name).

unsafe fn register_table( &self, builder: TableFunctionBuilder, ) -> Result<(), ExtensionError>

Register a table function.

unsafe fn register_sql_macro( &self, sql_macro: SqlMacro, ) -> Result<(), ExtensionError>

Register a SQL macro (scalar or table-returning).

unsafe fn register_cast( &self, builder: CastFunctionBuilder, ) -> Result<(), ExtensionError>

Register a custom type cast function.