Struct Connection 

pub struct Connection { /* private fields */ }

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::pg3::{Connection, Decode};

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

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

let name_index = query_result.columns.iter().position(|c| c.name == "name").unwrap();

for row in &query_result.rows {
    let name = String::decode(&row[name_index])?;
    println!("Found user {name}");
}

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

use spin_sdk::pg3::{Connection, Decode};

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

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

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

let count = i64::decode(&query_result.rows[0][0])?;

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

use spin_sdk::pg3::Connection;

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

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

A connection to a postgres database.

Implementations

impl Connection

pub fn open(address: &str) -> Result<Connection, Error>

Open a connection to the Postgres instance at address.

impl Connection

pub fn query( &self, statement: &str, params: &[ParameterValue], ) -> Result<RowSet, Error>

Query the database.

impl Connection

pub fn execute( &self, statement: &str, params: &[ParameterValue], ) -> Result<u64, Error>

Execute command to the database.

Trait Implementations

impl Debug for Connection

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.