2.3 KiB
2.3 KiB
Hrana client for TypeScript
This package implements a Hrana client for TypeScript. Hrana is the protocol for connecting to sqld using WebSocket or HTTP.
This package is intended mostly for internal use. Consider using the
@libsql/clientpackage, which will use Hrana automatically.
Usage
import * as hrana from "@libsql/hrana-client";
// Open a `hrana.Client`, which works like a connection pool in standard SQL
// databases.
const url = process.env.URL ?? "ws://localhost:8080"; // Address of the sqld server
const jwt = process.env.JWT; // JWT token for authentication
// Here we are using Hrana over WebSocket:
const client = hrana.openWs(url, jwt);
// But we can also use Hrana over HTTP:
// const client = hrana.openHttp(url, jwt);
// Open a `hrana.Stream`, which is an interactive SQL stream. This corresponds
// to a "connection" from other SQL databases
const stream = client.openStream();
// Fetch all rows returned by a SQL statement
const books = await stream.query("SELECT title, year FROM book WHERE author = 'Jane Austen'");
// The rows are returned in an Array...
for (const book of books.rows) {
// every returned row works as an array (`book[1]`) and as an object (`book.year`)
console.log(`${book.title} from ${book.year}`);
}
// Fetch a single row
const book = await stream.queryRow("SELECT title, MIN(year) FROM book");
if (book.row !== undefined) {
console.log(`The oldest book is ${book.row.title} from year ${book.row[1]}`);
}
// Fetch a single value, using a bound parameter
const year = await stream.queryValue(["SELECT MAX(year) FROM book WHERE author = ?", ["Jane Austen"]]);
if (year.value !== undefined) {
console.log(`Last book from Jane Austen was published in ${year.value}`);
}
// Execute a statement that does not return any rows
const res = await stream.run(["DELETE FROM book WHERE author = ?", ["J. K. Rowling"]])
console.log(`${res.affectedRowCount} books have been cancelled`);
// When you are done, remember to close the client
client.close();