node-mssql insert returning undefined recordset

Question

Select statements are working fine, but whenever I try an insert or update the recordset and affected values are undefined. The insert/update works in the DB, I just can't read the returned values.

var sql = require('mssql');
var config = {...};

sql.connect(config).then(function() {
  new sql.Request().query("INSERT INTO MyTable (Name, Age) VALUES ('John', 30)").then(function(recordset, affected) {
    console.log('Recordset: ' + recordset);
    console.log('Affected: ' + affected);
  }).catch(function(err) {
    console.log('Request error: ' + err);
  });
}).catch(function(err) {
  if (err) {
    console.log('SQL Connection Error: ' + err);
  }
});

The output to console is:

Recordset: undefined
Affected: undefined

I feel like I must be missing something really simple here.

Answer 1

As mentioned in the comments, INSERT statement doesn't return a recordset so recordset is undefined. Please see this section of the docs to learn more about how to get number of affected rows.

The problem with your code is you're expecting affected as a second argument from the promise, but promises does only support one argument. Because of that you must access number of affected rows this way:

var sql = require('mssql');
var config = {...};

sql.connect(config).then(function() {
  var request = new sql.Request();
  request.query("INSERT INTO MyTable (Name, Age) VALUES ('John', 30)").then(function(recordset) {
    console.log('Recordset: ' + recordset);
    console.log('Affected: ' + request.rowsAffected);
  }).catch(function(err) {
    console.log('Request error: ' + err);
  });
}).catch(function(err) {
  if (err) {
    console.log('SQL Connection Error: ' + err);
  }
});

Answer 2

If you want id to be output parameter

const sql = require("mssql/msnodesqlv8");
const pool = new sql.ConnectionPool(dbConfig);`
const poolConnect = pool.connect();    
let query = `INSERT INTO <table>(fields) VALUES(values);SELECT @id = SCOPE_IDENTITY()`
await poolConnect;
pool.request()
    .output("id", sql.Int)
    .query(query).then((err, result) => {
        console.log(result.output.id)
    }).catch(err => {
        console.log(err)
    })`