database-js-json

A database-js driver for JSON files.

About

This is a wrapper around the jl-sql-api, intended to be used with database-js for handling JSON files.

Our releases adopt Semantic Versioning.

Install

npm install database-js-json --save

Note: database-js must also be installed.

Basic Usage

const Connection = require( 'database-js' ).Connection;

( async () => {
    const connection = new Connection( 'json:///test.json' );
    try {
        const statement = await connection.prepareStatement("SELECT * WHERE user_name = ?");
        const rows = await statement.query('not_so_secret_user');
        console.log(rows);
    } catch (error) {
        console.log(error);
    } finally {
        await connection.close();
    }
} )();

Example

people.json

[
    { "name": "Alice", "age": 21 },
    { "name": "Bob", "age": 53 },
    { "name": "Jack", "age": 16 }
]

main.js

const dbjs = require( 'database-js' );
( async () => {
    let conn;
    try {
        conn = new dbjs.Connection( 'json:///people.json' );

        const st1 = conn.prepareStatement( 'SELECT *' );
        const r1 = await st1.query();
        console.log( r1 ); // same as people.json's content

        const st2 = conn.prepareStatement( 'SELECT name ORDER BY name DESC' );
        const r2 = await st2.query();
        console.log( r2 ); // [ { name: 'Jack' }, { name: 'Bob' }, { name: 'Alice' } ]

        const st3 = conn.prepareStatement( 'SELECT MAX(age) AS older' );
        const r3 = await st3.query();
        console.log( r3 ); // [ { older: 53 } ]

		// Inserting a row
		const st4 = conn.prepareStatement( 'INSERT VALUES { "name": "Mary", "age": 18 }' );
        await st4.execute();

		// Updating a row
		const st5 = conn.prepareStatement( 'UPDATE SET name = "Robert" WHERE name = "Bob"' );
        await st5.execute();

		// Deleting a row
		const st6 = conn.prepareStatement( 'DELETE WHERE name = "Alice"' );
        await st6.execute();

		// Now people.json is
		// [{"name":"Robert","age":53},{"name":"Jack","age":16},{"name":"Mary","age":18}]

    } catch ( err ) {
        console.error( err );
    } finally {
        if ( conn ) {
            await conn.close();
        }
    }
} )();

Basic Options

Options can be passed as arguments to the database connection string, in URL-format.

• charset: defines the charset (encoding) used to handle the JSON file

  • Defaults to utf-8
  • Example: const connection = new Connection( 'json:///test.json?charset=utf-16' );
  • Available in database-js-json version 1.0.0 or later

• checkOnConnect: whether it should check if the file exists when connecting to it

  • Defaults to true
  • Example: const connection = new Connection( 'json:///test.json?checkOnConnect=false' );
  • Accepts false, no or 0 as false
  • Available in database-js-json version 1.1.0 or later

Additional Options

Options from jl-sql-api can also be passed as arguments to the database connection.

Example: { tmpDir: "/path/to/dir" }

const connection = new Connection( 'json:///test.json?tmpDir=path/to/dir' );

When an option that belongs to a group is informed, it must have a dot.

Example: { tmpDir: "/path/to/dir", sortOptions: { inMemoryBufferSize: 32000 } }

const connection = new Connection( 'json:///test.json?tmpDir=path/to/dir&sortOptions.inMemoryBufferSize=32000' );

License

MIT (c) Thiago Delgado Pinto