CODEWITHSUNDEEP
mysqlnode.jsmodulereturn
Aviram Netanel
Aviram Netanel

Reputation: 13675

how to return \ retrieve a result from node.js module that does query to mysql?

I want to pass a result from mysql query to the level above...

I have this module: mySQLconnect.js:

var connection = require('mysql').createConnection({
  host : 'localhost',
  user : 'admin',
  password : ''
});

exports.querySelect = querySelect;

function querySelect(query){
    var result = connection.query(query, function(err, rows){
                           return (rows[0]);
                 });
    return result;
}

and when I call this function from outside, let's say from app.js:

var DBconnector = require('mySQLconnect');    
var result = DBconnector.querySelectUser("SELECT * FROM TB_USERS");

but the result I get is something else - it's an object from mysql.js module that's been received from:

connection.query(query, function(err, rows)

it has: _resultSet =null, and unreachable _results =[Array]

so it's no good...

I checked in node-mysql website, but didn't find what's connection.query returns.

any ideas how can I pass the result?

Upvotes: 0

Views: 645

Answers (1)

srquinn
srquinn

Reputation: 10501

You are wrapping an asynchronous call to the DB with a procedural function – a common mistake for nodejs beginners coming from a procedural language like PHP.

You can simplify your mySQLconnect.js module to the following:

var connection = require('mysql').createConnection({
  host : 'localhost',
  user : 'admin',
  password : ''
});

exports.querySelect = connection.query;

And then consume it thusly:

var DBconnector = require('mySQLconnect');
DBconnector.querySelect("SELECT * FROM TB_USERS", function (err, rows) {
  console.log(err || rows);
});

I would read up on callbacks, anonymous functions, and asynchronous flow patterns to help you wrap your head around this new style of coding. Good luck!

Upvotes: 1

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