Mysql connection not release

[youyi1314]

Hi,
Thanks for this ,
I use this for socket.io, but i found that the connection not release, may i know how can i release connection after used?

My code before

const db = function () {
const redisOptions = {};
        const cacheOptions = {
            expire: 2629746,// seconds, defaults to 30 days
            keyPrefix: "sql.", // default
            hashType: HashTypes.blake2b512, //default
            caching: Caching.SKIP //default
        };
        const pool = mysql.createPool({
            connectionLimit: 2,
            host: env.DB_HOST,
            user: env.DB_USERNAME,
            password: env.DB_PASSWORD,
            database: env.DB_DATABASE
        }).promise();
        const redis = asyncRedis.createClient();
        return new MysqlRedisAsync(
            pool,
            redis,
            cacheOptions
        );
}

[data, fields] = db.query('SELECT * FROM USERS');
console.log(data)

Thanks