add transaction handling to Client prototype

[billywhizz]

would it be okay to add transaction handling to the client as per the following patch, or something along these lines?

Client.prototype.begin = function(callback) {
    var client = this;
    this.query("SET autocommit=0", function(err, info) {
        if(err) {
            callback(err);
        }
        else {
            client.query("START TRANSACTION", function(err, info) {
                if(err) {
                    callback(err);
                }
                else {
                    callback(null, info);
                }
            });
        }
    });
};

Client.prototype.commit = function(callback) {
    var client = this;
    this.query("COMMIT", function(err, info) {
        if(err) {
            callback(err);
        }
        else {
            client.query("SET autocommit=1", function(err, info) {
                if(err) {
                    callback(err);
                }
                else {
                    callback(null, info);
                }
            });
        }
    });
};

Client.prototype.rollback = function(callback) {
    var client = this;
    this.query("ROLLBACK", function(err, info) {
        if(err) {
            callback(err);
        }
        else {
            client.query("SET autocommit=1", function(err, info) {
                if(err) {
                    callback(err);
                }
                else {
                    callback(null, info);
                }
            });
        }
    });
};

[felixge]

Hm, I think this kind of stuff would be better suited in a high-level wrapper. My goal with node-mysql is to only provide minimal abstraction on top of the low-level protocol handling.

Also, you probably want to issue both queries in your functions at the same time, otherwise a query could be inserted into the queue in between which would probably lead to undesirable side-affects.

[billywhizz]

OK. Thanks for the feedback.

[bminer]

I have added transaction support to node-mysql. Check out this project:

https://github.com/bminer/node-mysql-queues