Node.js の mysql2 で MariaDB のデータを削除 (Delete)

#! /usr/bin/node
// ---------------------------------------------------------------
//  maria_delete.js
//
//                  Jun/04/2020
//
// ---------------------------------------------------------------
var mysql = require('mysql2')

// ---------------------------------------------------------------
async function main(id_in)
{
    const dotenv = require('dotenv')
    dotenv.config()
    const user = `${process.env.user}`
    const password = `${process.env.password}`
    const data_base = `${process.env.data_base}`

    var conn = await mysql.createConnection ({
        host: 'localhost',
        user: user,
        password: password,
        database: data_base
        })

    const command = "delete from cities where id = '" + id_in + "'"

    await conn.execute(command)
    conn.end()
    console.error ("*** 終了 ***")
}

// ---------------------------------------------------------------
console.error ("*** 開始 ***")
const id_in = process.argv[2]
console.log (id_in)
main(id_in)
// ---------------------------------------------------------------

export NODE_PATH=/usr/lib/node_modules
./maria_delete.js t3327