Mysql: Ability to log all queries

[q42jaap]

I want to plugin in nodejs' debug into node-mysql, in order to log all the queries. I'd rather not wrap all the calls to node-mysql, because of the formatting and the many combinations of arguments.

I'm using bluebird to make promises so I can't really use the return value of connection.query(). connection.queryAsync() doesn't give me access to the return object.

It would be nice if there was a way to plug it in, maybe an event on the connection/pool object. That way I don't have to think about writing the code that does the logging.

[dougwilson]

Hi @q42jaap , that seems like a pretty good idea. Any proposal on what would be a good way to go about it that would satisfy your use-case?

[q42jaap]

Hi, sorry it took a while for me to respond.
I would think a Connection level event system seems a good idea.

connection.on('query', function(query) { console.log(query.sql) });

as an added bonus, it may be nice to also add it to a Pool:

pool.on('query', function(query) { console.log(query.sql) });

Something along these lines?

[ayanth]

+1

[dougwilson]

Perhaps the following code may work?

connection.on('enqueue', function (sequence) {
  if (sequence instanceof mysql.Sequences.Query) {
    console.log(sequence.sql);
  }
});

The response didn't actually lay-out the use-case, only really what you envisioned the API to be. Can you please layout the use-case for the event? For example, why emit queries both in the enqueue event as well as again on a query event?

[q42jaap]

Hi @dougwilson,
I did not know this! This may very well work for my use case. I just want to see all the query's while developing. Enqueue is probably exactly what I'm looking for.

As a last thing, does the pool also have this enqueue event?

[dougwilson]

As a last thing, does the pool also have this enqueue event?

It does, but it has a different meaning: it means a connection request has been enqueued. If you want to monitor from the pool-level, just combine the connection event on the pool plus the enqueue event on the connection:

pool.on('connection', function (connection) {
  connection.on('enqueue', function (sequence) {
    if (sequence instanceof mysql.Sequences.Query) {
      console.log(sequence.sql);
    }
  });
});

[q42jaap]

This is super helpful, thanks a lot!

[dougwilson]

No problem!

[Telokis]

@dougwilson This doesn't seem to work anymore. I am getting TypeError: Cannot read property 'Query' of undefined

Here is the code:

        if (nconf.get('dev')) {
            Database.pool.on('connection', (connection) => {
                connection.on('enqueue', (sequence) => {
                    if (sequence instanceof mysql.Sequences.Query) {
                        winston.info(sequence.sql);
                    }
                });
            });
        }

[wheresvic]

This is how I am doing it now :)

  pool.on('connection', function(connection) {
    connection.on('enqueue', function(sequence) {
      // if (sequence instanceof mysql.Sequence.Query) {
      if ('Query' === sequence.constructor.name) {
        console.log(sequence.sql);
      }
    });
  });