Bluebird, node-mysql, pooling, and disposing

Question

Currently trying to implement a different approach to connecting to my database using promises and pooling. This is what I have as of the moment:

// databaseConnection.js
var configDB = require('./database.js');
var mysql = require('promise-mysql');

var pool = mysql.createPool(configDB.connectionData);

function getSqlConnection() {
    return pool.getConnection(configDB.connectionData).disposer(function(connection) {
        connection.release();
    });
}

module.exports = getSqlConnection;

Then I use the query like this:

#sqlQuery.js
var Promise = require("bluebird");
var getSqlConnection = require('./databaseConnection')
Promise.using(getSqlConnection(), function(connection) {
    return connection.query("SELECT * FROM EXAMPLE_TABLE").then(function(row) {
        return process(rows);
    }
}

I'm using this library which is just node-mysql wrapped with BlueBird promises. With that, I wanted to take advantage of BlueBird's disposing and using capability so I would only be connected to the DB when I needed to be.

Currently though I'm getting an error from Connection.js of mysql stating: cb is not a function. Based on this question I have somewhat of an idea of what I'm doing wrong but I'm not sure how I would go about using that with BlueBird's dispose/using paradigm. Thanks in advance for anyone that can help!

In your `sqlQuery.js` code you are calling `getSqlConnection()` - without passing the `cb` (callback?) argument. What is this `cb` used for? — ishmaelMakitla, Aug 12 '16 at 07:19
Sorry about that. I copied that code from my modified source. What's up there now should be the original. I don't use a callback in my code. Nor does it mention requiring one in the `node-mysql` documentation — wootencl, Aug 12 '16 at 13:06
OK, now since you do not have `cb` there anymore - are you still getting the same error message? — ishmaelMakitla, Aug 12 '16 at 13:23
That is correct. Even more curious I just found this BlueBird example that seems to resemble mine: https://github.com/petkaantonov/bluebird/blob/master/docs/docs/working-with-callbacks.md#mysql — wootencl, Aug 12 '16 at 13:26

score 0 · Answer 1 · answered Aug 12 '16 at 13:31

0

Huge lack of oversight on my part. The following line:

return pool.getConnection(configDB.connectionData).disposer...

should be:

return pool.getConnection().disposer...

Sorry about that. Still getting an error for connection.release not being a function which is strange but at least I can move forward with debugging that.

answered Aug 12 '16 at 13:31

wootencl

585
4
15

Just to confirm - so you say even this did not help? – ishmaelMakitla Aug 12 '16 at 13:41
It did help. Just getting a different error now. Researching a possible fix at the moment – wootencl Aug 12 '16 at 13:43
Try changing from `getConnection()`... and rather use `getConnectionAsync().disposer...`, see if this helps clear the error. – ishmaelMakitla Aug 12 '16 at 13:49
`getConnectionAsync()` isn't available in `node-mysql` pools from what I can tell – wootencl Aug 12 '16 at 14:00
1

I was looking at [this related post](http://stackoverflow.com/questions/24797314/how-will-a-promisified-mysql-module-work-with-nodejs). – ishmaelMakitla Aug 12 '16 at 14:05
Appreciate the help! And yeah. Stumbled upon a similar post. Looking like I'm going to move away from using `node-promise-mysql` and just manually bluebirdify mysql – wootencl Aug 12 '16 at 14:16

Bluebird, node-mysql, pooling, and disposing

1 Answers1