promises2.js

sql.connect(config.sqlConfig).then(pool => {
    this.pool = pool;
    pool.request().query `select * from dbo.Groups`
})
.then(iSuccesfullyGetGroups.bind(this), errorConnect)
.then(startParsing.bind(this))

function iSuccesfullyGetGroups(result){
  const groups = result.recordset;

  return new Promise((resolve, reject) => {
    if (groups.length > 0) {
        VK.auth.user().then(token => {
            for (const group of groups) {
                VK.call('execute.getPosts', {
                    mode: "getOffset",
                    groupId: group.GroupId,
                    topicId: group.TopicId
                }).then(res => {
                    this.pool.request().query`UPDATE dbo.Groups SET offset = ${res.count} WHERE Id = ${group.Id}`.then(() => {resolve(true)})
                }).catch(err => { reject(err) });
            }
        });
    }
  }).bind(this);
}

function startParsing(pool) {
    setInterval(() => {
      pool.request().query(`select * from dbo.Groups`).then(successGetGroups.bind(this));
    }, 5000);
}

function errorConnect(err) {
  console.dir(err);
    sql.close();
}