# pgvector-rust
[pgvector](https://github.com/ankane/pgvector) support for Rust
Supports [Rust-Postgres](https://github.com/sfackler/rust-postgres) and [Diesel](https://github.com/diesel-rs/diesel)
[](https://github.com/ankane/pgvector-rust/actions)
## Getting Started
Follow the instructions for your database library:
- [Rust-Postgres](#rust-postgres)
- [Diesel](#diesel)
## Rust-Postgres
Add this line to your application’s `Cargo.toml` under `[dependencies]`:
```toml
pgvector = { version = "0.1", features = ["postgres"] }
```
Create a vector from a `Vec<f32>`
```rust
let vec = pgvector::Vector::from(vec![1.0, 2.0, 3.0]);
```
Insert a vector
```rust
client.execute("INSERT INTO table (column) VALUES ($1)", &[&vec])?;
```
Get the nearest neighbor
```rust
let row = client.query_one("SELECT * FROM table ORDER BY column <-> $1 LIMIT 1", &[&vec])?;
```
Retrieve a vector
```rust
let row = client.query_one("SELECT column FROM table LIMIT 1", &[])?;
let vec: pgvector::Vector = row.get(0);
```
Use `Option` if the value could be `NULL`
```rust
let res: Option<pgvector::Vector> = row.get(0);
```
Convert a vector to a `Vec<f32>`
```rust
let f32_vec = vec.to_vec();
```
## Diesel
Add this line to your application’s `Cargo.toml` under `[dependencies]`:
```toml
pgvector = { version = "0.1", features = ["diesel"], default-features = false }
```
And add this line to your application’s `diesel.toml` under `[print_schema]`:
```toml
import_types = ["diesel::sql_types::*", "pgvector::sql_types::*"]
```
Create a migration
```sh
diesel migration generate create_vector_extension
```
with `up.sql`:
```sql
CREATE EXTENSION vector
```
and `down.sql`:
```sql
DROP EXTENSION vector
```
Run the migration
```sql
diesel migration run
```
You can now use the `vector` type in future migrations
```sql
CREATE TABLE items (
factors VECTOR(3)
)
```
For models, use:
```rust
pub struct Item {
pub factors: Option<pgvector::Vector>
}
```
Create a vector from a `Vec<f32>`
```rust
let factors = pgvector::Vector::from(vec![1.0, 2.0, 3.0]);
```
Insert a vector
```rust
let new_item = Item {
factors: Some(factors)
};
diesel::insert_into(items::table)
.values(&new_item)
.get_result(conn)
.expect("Error saving new item")
```
Convert a vector to a `Vec<f32>`
```rust
let f32_factors = factors.to_vec();
```
## History
View the [changelog](https://github.com/ankane/pgvector-rust/blob/master/CHANGELOG.md)
## Contributing
Everyone is encouraged to help improve this project. Here are a few ways you can help:
- [Report bugs](https://github.com/ankane/pgvector-rust/issues)
- Fix bugs and [submit pull requests](https://github.com/ankane/pgvector-rust/pulls)
- Write, clarify, or fix documentation
- Suggest or add new features
To get started with development:
```sh
git clone https://github.com/ankane/pgvector-rust.git
cd pgvector-rust
cargo test --features postgres
cargo test --features diesel
```