duckdb/README.md

DuckDB node.js API

> [!WARNING]
> The original DuckDB <> Node.js bindings in this package are deprecated in favor of the new and shiny `@duckdb/node-api` package. Currently, the plan is to release this package `duckdb-node` for the last time for the DuckDB 1.4.x (~Fall 2025) series but *not* for the DuckDB 1.5.x series (~Early 2026) any more. Please [contact](https://duckdblabs.com/contact/) DuckDB Labs if you absolutely require updates after that.

# DuckDB Node Bindings

This package provides a Node.js API for [DuckDB](https://github.com/duckdb/duckdb), the "SQLite for Analytics". The API for this client is somewhat compliant to the SQLite Node.js client for easier transition (and transition you must eventually).

Load the package and create a database object:

```js
var duckdb = require('duckdb');

var db = new duckdb.Database(':memory:'); // or a file name for a persistent DB
```

Then you can run a query:

```js
db.all('SELECT 42 AS fortytwo', function(err, res) {
  if (err) {
    console.warn(err);
  }
  console.log(res[0].fortytwo)
});
```

Other available methods are `each`, where the callback is invoked for each row, `run` to execute a single statement without results and `exec`, which can execute several SQL commands at once but also does not return results. All those commands can work with prepared statements, taking the values for the parameters as additional arguments. For example like so:

```js
db.all('SELECT ?::INTEGER AS fortytwo, ?::STRING as hello', 42, 'Hello, World', function(err, res) {
  if (err) {
    console.warn(err);
  }
  console.log(res[0].fortytwo)
  console.log(res[0].hello)
});
```

However, these are all shorthands for something much more elegant. A database can have multiple `Connection`s, those are created using `db.connect()`.

```js
var con = db.connect();
```

You can create multiple connections, each with their own transaction context.


`Connection` objects also contain shorthands to directly call `run()`, `all()` and `each()` with parameters and callbacks, respectively, for example:

```js
con.all('SELECT 42 AS fortytwo', function(err, res) {
  if (err) {
    console.warn(err);
  }
  console.log(res[0].fortytwo)
});
```

From connections, you can create prepared statements (and only that) using `con.prepare()`:

```js
var stmt = con.prepare('select ?::INTEGER as fortytwo');
``` 

To execute this statement, you can call for example `all()` on the `stmt` object:

```js
stmt.all(42, function(err, res) {
  if (err) {
    console.warn(err);
  }
  console.log(res[0].fortytwo)
});
```

You can also execute the prepared statement multiple times. This is for example useful to fill a table with data:

```js
con.run('CREATE TABLE a (i INTEGER)');
var stmt = con.prepare('INSERT INTO a VALUES (?)');
for (var i = 0; i < 10; i++) {
  stmt.run(i);
}
stmt.finalize();
con.all('SELECT * FROM a', function(err, res) {
  if (err) {
    console.warn(err);
  }
  console.log(res)
});
```

`prepare()` can also take a callback which gets the prepared statement as an argument:

```js
var stmt = con.prepare('select ?::INTEGER as fortytwo', function(err, stmt) {
  stmt.all(42, function(err, res) {
    if (err) {
      console.warn(err);
    }
    console.log(res[0].fortytwo)
  });
});
```

## Supported Node versions
We actively support only LTS and In-Support Node versions, as per July 2023, they are: Node 18, Node 20 and Node 21. For OSX and Linux targets, also Node 22 is available.
Release schedule for Node.js can be checked here: https://github.com/nodejs/release#release-schedule.

We currently bundle and test DuckDB also for Node 12, 14, 16, 17 and 19. We plan of going so going forward as long as the tooling supports it.
As per July 2023, Node 15 has been removed from the supported versions.

## Development

### First install:

To install all the dev dependencies of the project, run `npm install` (this uses package.json)
You might want to add the `--ignore-scripts` option if you don't care about building the package for now and just want to install the dependencies.

### Tests:
Tests are located in `test` and can be run with `npm test`
To run a single test, you can use `npm test -- --grep "name of test as given in describe"`

### Additional notes:
To build the NodeJS package from source, when on Windows, requires the following extra steps:
- Set `OPENSSL_ROOT_DIR` to the root directory of an OpenSSL installation
- Supply the `STATIC_OPENSSL=1` option when executing `make`, or set `-DOPENSSL_USE_STATIC_LIBS=1` manually when calling `cmake`