Struct Connection 

pub struct Connection(/* private fields */);

Available on crate feature pg only.

An open connection to a PostgreSQL database.

Examples

Load a set of rows from a local PostgreSQL database, and iterate over them.

use spin_sdk::pg::{Connection, Decode};

let db = Connection::open("host=localhost user=postgres password=my_password dbname=mydb").await?;

let mut query_result = db.query(
    "SELECT * FROM users WHERE age >= $1",
    &[min_age.into()]
).await?;

while let Some(row) = query_result.next().await {
    let name = row.get::<String>("name").unwrap();
    println!("Found user {name}");
}

query_result.result().await?;

Perform an aggregate (scalar) operation over a table. The result set contains a single column, with a single row.

use spin_sdk::pg::{Connection, Decode};

let db = Connection::open("host=localhost user=postgres password=my_password dbname=mydb").await?;

let query_result = db.query("SELECT COUNT(*) FROM users", &[]).await?;

assert_eq!(1, query_result.columns().len());
assert_eq!("count", query_result.columns()[0].name);

let rows = query_result.collect().await?;

assert_eq!(1, rows.len());

let count = &rows[0][0];

Delete rows from a PostgreSQL table. This uses Connection::execute() instead of the query method.

use spin_sdk::pg::Connection;

let db = Connection::open("host=localhost user=postgres password=my_password dbname=mydb").await?;

let rows_affected = db.execute(
    "DELETE FROM users WHERE name = $1",
    &["Baldrick".to_owned().into()]
).await?;

Implementations

impl Connection

pub async fn open(address: impl Into<String>) -> Result<Self, Error>

Open a connection to a PostgreSQL database.

The address may be in connection string form ("host=... dbname=...") or in URL form ("postgres://<host>/<dbname>?...").

This constructor does not support options such as custom CA roots. See Connection::open_with_options for a more flexible constructor.

pub async fn open_with_options( address: impl AsRef<str>, options: OpenOptions, ) -> Result<Self, Error>

Open a connection to a PostgreSQL database.

The address may be in connection string form ("host=... dbname=...") or in URL form ("postgres://<host>/<dbname>?...").

The options parameter allows for passing options not available in the address string.

pub async fn query( &self, statement: impl Into<String>, params: impl Into<Vec<ParameterValue>>, ) -> Result<QueryResult, Error>

Query the database.

Use this function for queries that return rows (typically SELECT queries). For side-effectful queries, see Connection::execute.

pub async fn execute( &self, statement: impl Into<String>, params: impl Into<Vec<ParameterValue>>, ) -> Result<u64, Error>

Execute a command against the database.

Use this function for side-effectful queries (such as INSERT or DELETE queries). For queries that return row data, see Connection::query.

pub fn into_inner(self) -> Connection

Extracts the underlying Wasm Component Model resource for the connection.