ba28999d05
This PR adds the `datetime` function, with all the support currently
that date/time have for modifiers, and `julianday` function, as well as
some additional modifiers for date/time/datetime.
There are a couple considerations here, I left a couple comments but
essentially there is going to have to be some more work done to track
the state of the expression during the application of modifiers, to
handle a bunch of edge-cases like re-applying the same timezone modifier
to itself, or converting an integer automatically assumed to be
julianday, into epoch, or `ceiling`/`floor` which will determine
relative addition of time in cases like
```
2024-01-31 +1 month = 2024-03-02
```
which was painful enough to get working to begin with.
I couldn't get the `julianday_converter` library to get the exact same
float precision as sqlite, so function is included that matches their
output, for some reason floating point math + `.floor()` would give the
correct result. They seem to 'round' to 8 decimal places, and I was able
to get this to work with the same output as sqlite, except in cases like
`2234.5`, in which case we return `2234.5000000` because of the `fmt`
precision:
```rust
pub fn exec_julianday(time_value: &OwnedValue) -> Result<String> {
let dt = parse_naive_date_time(time_value);
match dt {
// if we did something heinous like: parse::<f64>().unwrap().to_string()
// that would solve the precision issue, but dear lord...
Some(dt) => Ok(format!("{:.1$}", to_julian_day_exact(&dt), 8)),
None => Ok(String::new()),
}
}
```
Suggestions would be appreciated on the float precision issue.
Reviewed-by: Sonny <14060682+sonhmai@users.noreply.github.com>
Closes #600
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| .github/workflows | ||
| bindings | ||
| cli | ||
| core | ||
| docs/internals | ||
| macros | ||
| perf/latency | ||
| scripts | ||
| simulator | ||
| sqlite3 | ||
| test | ||
| testing | ||
| vendored/sqlite3-parser | ||
| .github.json | ||
| .gitignore | ||
| Cargo.lock | ||
| Cargo.toml | ||
| CHANGELOG.md | ||
| COMPAT.md | ||
| CONTRIBUTING.md | ||
| flake.lock | ||
| flake.nix | ||
| LICENSE.md | ||
| limbo.png | ||
| Makefile | ||
| PERF.md | ||
| Pipfile | ||
| Pipfile.lock | ||
| README.md | ||
| rust-toolchain.toml | ||
Limbo
Limbo is a work-in-progress, in-process OLTP database management system, compatible with SQLite.
Features
- In-process OLTP database engine library
- Asynchronous I/O support on Linux with
io_uring - SQLite compatibility (status)
- SQL dialect support
- File format support
- SQLite C API
- JavaScript/WebAssembly bindings (wip)
- Support for Linux, macOS, and Windows
Getting Started
CLI
Install limbo with:
curl --proto '=https' --tlsv1.2 -LsSf \
https://github.com/tursodatabase/limbo/releases/latest/download/limbo-installer.sh | sh
Then use the SQL shell to create and query a database:
$ limbo database.db
Limbo v0.0.6
Enter ".help" for usage hints.
limbo> CREATE TABLE users (id INT PRIMARY KEY, username TEXT);
limbo> INSERT INTO users VALUES (1, 'alice');
limbo> INSERT INTO users VALUES (2, 'bob');
limbo> SELECT * FROM users;
1|alice
2|bob
JavaScript (wip)
Installation:
npm i limbo-wasm
Example usage:
import { Database } from 'limbo-wasm';
const db = new Database('sqlite.db');
const stmt = db.prepare('SELECT * FROM users');
const users = stmt.all();
console.log(users);
Python (wip)
pip install pylimbo
Example usage:
import limbo
con = limbo.connect("sqlite.db")
cur = con.cursor()
res = cur.execute("SELECT * FROM users")
print(res.fetchone())
Developing
Build and run limbo cli:
cargo run --package limbo --bin limbo database.db
Run tests:
cargo test
Test coverage report:
cargo tarpaulin -o html
Note
Generation of coverage report requires tarpaulin binary to be installed. You can install it with
cargo install cargo-tarpaulin
Tip
If coverage fails with "Test failed during run" error and all of the tests passed it might be the result of tarpaulin bug. You can temporarily set dynamic libraries linking manually as a workaround, e.g. for linux
LD_LIBRARY_PATH="$(rustc --print=target-libdir)" cargo tarpaulin -o html.
Run benchmarks:
cargo bench
Run benchmarks and generate flamegraphs:
echo -1 | sudo tee /proc/sys/kernel/perf_event_paranoid
cargo bench --bench benchmark -- --profile-time=5
FAQ
How is Limbo different from libSQL?
Limbo is a research project to build a SQLite compatible in-process database in Rust with native async support. The libSQL project, on the other hand, is an open source, open contribution fork of SQLite, with focus on production features such as replication, backups, encryption, and so on. There is no hard dependency between the two projects. Of course, if Limbo becomes widely successful, we might consider merging with libSQL, but that is something that will be decided in the future.
Publications
- Pekka Enberg, Sasu Tarkoma, Jon Crowcroft Ashwin Rao (2024). Serverless Runtime / Database Co-Design With Asynchronous I/O. In EdgeSys ‘24. [PDF]
- Pekka Enberg, Sasu Tarkoma, and Ashwin Rao (2023). Towards Database and Serverless Runtime Co-Design. In CoNEXT-SW ’23. [PDF] [Slides]
Contributing
We'd love to have you contribute to Limbo! Check out the contribution guide to get started.
License
This project is licensed under the MIT license.
Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in Limbo by you, shall be licensed as MIT, without any additional terms or conditions.