var mysql = require('mysql');

var connection = mysql.createConnection({
host: 'localhost',
user: 'username',
password: 'pass',
database: 'db',
});

var q = 'SELECT * FROM table1';
var data_wanted = [];

connection.query(q, function(err, result) {

    for(var i = 0; i < 100; i++) {     //let's say there are 100 rows in table1
        var manipulated_data = result + 1;
        data_wanted.push(manipulated_data);
    }

});

var q2 = 'INSERT into table2 (number) VALUES ?';

connection.query(q2, [data_wanted], function(err, result) {
    //bulk inserts data_wanted[]
});

console.log(data_wanted) //outputs []; still empty, even after 1st query