4. External types

Types referenced by the generated module pages but owned elsewhere — the duckdb_stmt cursor module, the raw duckdb C binding, and daslang’s daslib/sql core. This page anchors their labels so the generated pages link without dangling references; follow the upstream links for the authoritative definitions. (Daslang-core types such as Result / Option resolve against the daslang documentation via intersphinx.)

4.1. duckdb_stmt::DuckStmt

The provider statement handle spliced into _sql-emitted bind/reader blocks — a cursor over a prepared statement and its materialized result. Unlike SQLite’s step-cursor sqlite3_stmt?, DuckDB’s C API executes to a materialized duckdb_result read by (column, row), so the handle carries the prepared statement, the result pointer, and the current row. User code never constructs one; the run_select family owns its lifecycle.

4.2. duckdb::duckdb_connection

The raw C-API connection handle (DuckDB C API), owned by SqlRunner and passed to duckdb_* functions when dropping below the boost layer.

4.3. sql::SqlType

Daslang’s abstract SQL storage class (Integer / Real / Text / Blob / Null, from daslib/sql). The provider renders it to DuckDB spellings via duckdb_sql_type — BIGINT / DOUBLE / VARCHAR / BLOB.

4.4. sql::SqlError

Option<string> from daslib/sql — none on success, some(errmsg) on failure. The return type of every try_* helper that has no payload.