问MySQL与NodeJS后端和ReactJS FrontEnd的集成

EN

var sql = require('mssql');

var config = {
    user: "databaseAccountUsername",
    password: "databaseAccountPassword",
    server: "databaseServerAddress",
    database: "databaseName",
    options: {
        encrypt: false
    }
}

const pool = new sql.ConnectionPool(config);
    pool.connect(err => {
    if(err) {
        console.log(err)
    }
});

function getCustomers() {
    var request = new sql.Request(pool);
    request.query("SELECT customer_id, first_name FROM customers")
    .then((result) => {
        res.end(JSON.stringify(result.recordsets[0]));
    })
    sql.close();
}