Agfdhyk

I use the event to execute a query in mysql database with nodejs, the first 5 times execute normally, but after 5 times return an error "Lock wait timeout exceeded; try restarting transaction". What happened and how can i solve this?
I use Mysql database.

 emitter.on('mysql.transact', function(data, callback) {



    inTransaction(pool, 

        function(db, next) {

            //console.log('======');

            //console.log(data.q);

            //console.log(data.v);

            db.query(data.q, data.v, function(err) {

                if (err) return next(err);

                return callback(null,data);

        })}, 

        function(err) {

            console.log("All done, transaction ended and connection released");

            console.log(err);

        }

    );

}); 



function inTransaction(pool, body, callback) {

    withConnection(pool, function(db, done) {

        //console.log('123');

        //console.log(db);

        db.beginTransaction(function(err) {

            if (err) return done(err);



            body(db,finished)

        })



        // Commit or rollback transaction, then proxy callback

        function finished(err) {

            var context = this;

            var args = arguments;



            if (err) {

                if (err == 'rollback') {

                    args[0] = err = null;

                }

                db.rollback(function() { done.apply(context, args) });

            } else {

                db.commit(function(err) {

                    args[0] = err;

                    done.apply(context, args)

                })

            }

        }

    }, callback)

}



function withConnection(pool, body, callback) {



    pool.getConnection(function(err, db) {

        if (err) return callback(err);



        body(db, finished); 

        function finished() {

            db.release();

            callback.apply(this, arguments);

        }

    })

}

=========

Here is a query that i tried to execute with nodejs

    var q = ' UPDATE data_alarm set HideAlarmFrom = NULL, '+

                        ' HideAlarmText = NULL ' +

                        ' Where  VariableID in (select VariableID from  dbo_v_reportvariables' +

                        ' where ClientID = ? ' +

                        ' and SiteID in (select SiteID from dbo_v_accesslist where UserID = ? ) ) ';



var v = [req.user.ClientID,req.user.UserID];



exp.emitter.emit('mysql.transact',{ q: q, v : v }, function(err, data) {

                if (err) {

                    res.status(500).json({ error : err });  

                } else {

                    res.status(200).json(data);  

                }

           });