Lupdo-sqlite

Lupdo Driver For Sqlite. Api

Supported Databases

• sqlite/sqlite3

Third Party Library

Lupdo-sqlite, under the hood, uses stable and performant npm packages:

• better-sqlite3

Usage

Base Example

const { createSqlitePdo } = require('lupdo-sqlite');
// ES6 or Typescrypt
import { createSqlitePdo } from 'ludpo-sqlite';

const pdo = createSqlitePdo({ path: ':memory' }, { min: 2, max: 3 });
const run = async () => {
    const statement = await pdo.query('SELECT 2');
    const res = statement.fetchArray().all();
    console.log(res);
    await pdo.disconnect();
};

run();

Driver Options

https://github.com/WiseLibs/better-sqlite3/blob/master/docs/api.md#new-databasepath-options

new required option added:

• path: string

new optional option added

• wal: boolean [default false]
• synchronous: string [default NORMAL works only when WAL enabled]
• maxSize: number [default undefined] (MB)
• onWalError: (err) => void [default undefined]

When WAL is disabled default journal_mode will be delete for database file and memory for memory database.
When WAL is enabled and maxSize is defined every 5 seconds lupdo-sqlite will check if WAL file is bigger than maxSize, if size is greater than maxSize wal_checkpoint(TRUNCATE) is called.
When WAL watcher get an error it will call your custom onWalError callback with the original error.
Sqlite only creates the WAL file when it is needed, which is why it may not exist, here is an example:

const pdo = createSqlitePdo(
    {
        path: 'sqlitefile.db',
        wal: true,
        maxSize: 100,
        onWalError: (err: any) => {
            if (err.code !== 'ENOENT') {
                // log the error on your application
            }
        }
    },
    { min: 2, max: 3 }
);

Better Sqlite Overrides

By default Ludpo-sqlite enable db.defaultSafeIntegers(true) and statement.safeIntegers(true). https://github.com/WiseLibs/better-sqlite3/blob/2194095aa1183e9c21d28eafadeac0d4d4d42625/docs/integer.md#getting-bigints-from-the-database

Internally lupdo-sqlite convert bigint to normal number if precision will be preserved.

Note Custom Aggregate and Function must be adapted as required if using numbers.

Parameters Binding

Lupdo-sqlite ignore type definition of TypeBinding parameter.
Lupdo-sqlite does not support array of parameters.

Not Integer Numbers

Warning All non-integer numbers are returned as strings, no precision is guaranteed, you can choose which cast to apply in your application.

Kill Connection

Lupdo-sqlite do not support kill query, if you need to perform very slow queries, you should implement worker threads by yourself.

Note you can use better-sqlite3 native api, retrieving a raw connection from the pool with pdo.getRawPoolConnection(). Do not forget to release rawPoolConnection before stop the job, otherwise the pool will be stuck.

SqliteDriver Create Function & Aggregate

SqliteDriver expose two static Method in order to register custom aggregates and functions.

Here You can find more details on aggregate and functions Options.

Note The SqliteDriver.createFunction(name, options) differs from the original better-sqlite3.function(name, [options], function), it accepts only a name and a config, config must contains execute function.

const { createSqlitePdo, SqliteDriver } = require('lupdo-sqlite');
// ES6 or Typescrypt
import { createSqlitePdo, SqliteDriver } from 'ludpo-sqlite';

SqliteDriver.createAggregate('max_len', {
    start: 0,
    step: (context: number, nextValue: string) => {
        if (nextValue.length > context) {
            return nextValue.length;
        }
        return context;
    }
});

SqliteDriver.createFunction('add2', {
    execute(a, b) {
        return a + b;
    }
});

const pdo = createSqlitePdo({ path: './test.db' });

await pdo.query('SELECT max_len(name) FROM companies;');
await pdo.query('SELECT add2(name, gender) FROM users;');