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