duckdb-rs
duckdb-rs is an ergonomic wrapper for using duckdb from Rust. It attempts to expose an interface similar to rusqlite. Actually the initial code and even this README is forked from rusqlite as duckdb also tries to expose a sqlite3 compatible API.
use duckdb::{params, Connection, Result};
// In your project, we need to keep the arrow version same as the version used in duckdb.
// Refer to https://github.com/wangfenjin/duckdb-rs/issues/92
// You can either:
use duckdb::arrow::record_batch::RecordBatch;
// Or in your Cargo.toml, use * as the version; features can be toggled according to your needs
// arrow = { version = "*", default-features = false, features = ["prettyprint"] }
// Then you can:
// use arrow::record_batch::RecordBatch;
use duckdb::arrow::util::pretty::print_batches;
#[derive(Debug)]
struct Person {
id: i32,
name: String,
data: Option<Vec<u8>>,
}
fn main() -> Result<()> {
let conn = Connection::open_in_memory()?;
conn.execute_batch(
r"CREATE SEQUENCE seq;
CREATE TABLE person (
id INTEGER PRIMARY KEY DEFAULT NEXTVAL('seq'),
name TEXT NOT NULL,
data BLOB
);
")?;
let me = Person {
id: 0,
name: "Steven".to_string(),
data: None,
};
conn.execute(
"INSERT INTO person (name, data) VALUES (?, ?)",
params![me.name, me.data],
)?;
// query table by rows
let mut stmt = conn.prepare("SELECT id, name, data FROM person")?;
let person_iter = stmt.query_map([], |row| {
Ok(Person {
id: row.get(0)?,
name: row.get(1)?,
data: row.get(2)?,
})
})?;
for person in person_iter {
println!("Found person {:?}", person.unwrap());
}
// query table by arrow
let rbs: Vec<RecordBatch> = stmt.query_arrow([])?.collect();
print_batches(&rbs).unwrap();
Ok(())
}
Notes on building duckdb and libduckdb-sys
libduckdb-sys
is a separate crate from duckdb-rs
that provides the Rust
declarations for DuckDB's C API. By default, libduckdb-sys
attempts to find a DuckDB library that already exists on your system using pkg-config, or a
Vcpkg installation for MSVC ABI builds.
You can adjust this behavior in a number of ways:
- If you use the
bundled
feature,libduckdb-sys
will use the cc crate to compile DuckDB from source and link against that. This source is embedded in thelibduckdb-sys
crate and as we are still in development, we will update it regularly. After we are more stable, we will use the stable released version from duckdb. This is probably the simplest solution to any build problems. You can enable this by adding the following in yourCargo.toml
file:[dependencies.duckdb] version = "0.1" features = ["bundled"]
- When linking against a DuckDB library already on the system (so not using any of the
bundled
features), you can set theDUCKDB_LIB_DIR
environment variable to point to a directory containing the library. You can also set theDUCKDB_INCLUDE_DIR
variable to point to the directory containingduckdb.h
. - Installing the duckdb development packages will usually be all that is required, but
the build helpers for pkg-config
and vcpkg have some additional configuration
options. The default when using vcpkg is to dynamically link,
which must be enabled by setting
VCPKGRS_DYNAMIC=1
environment variable before build.
Binding generation
We use bindgen to generate the Rust
declarations from DuckDB's C header file. bindgen
recommends
running this as part of the build process of libraries that used this. We tried
this briefly (duckdb
0.10.0, specifically), but it had some annoyances:
- The build time for
libduckdb-sys
(and thereforeduckdb
) increased dramatically. - Running
bindgen
requires a relatively-recent version of Clang, which many systems do not have installed by default. - Running
bindgen
also requires the DuckDB header file to be present.
So we try to avoid running bindgen
at build-time by shipping
pregenerated bindings for DuckDB.
If you use the bundled
features, you will get pregenerated bindings for the
bundled version of DuckDB. If you want to run bindgen
at buildtime to
produce your own bindings, use the buildtime_bindgen
Cargo feature.
Contributing
See to Contributing.md
Checklist
- Run
cargo fmt
to ensure your Rust code is correctly formatted. - Run
cargo clippy --fix --allow-dirty --all-targets --workspace --all-features -- -D warnings
to fix all clippy issues. - Ensure
cargo test --all-targets --workspace --features "modern-full extensions-full"
reports no failures.
TODOs
- Refactor the ErrorCode part, it's borrowed from rusqlite, we should have our own
- Support more type
- Update duckdb.h
- Adjust the code examples and documentation
- Delete unused code / functions
- Add CI
- Publish to crate
License
DuckDB and libduckdb-sys are available under the MIT license. See the LICENSE file for more info.