node.js 函数陷入无限循环

Question

I have this:

 var getTexts = new cronJob('* 5 * * * *', function() {
    let weekday = ['SUNDAY', 'MONDAY', 'TUESDAY', 'WEDNESDAY', 'THURSDAY', 'FRIDAY', 'SATURDAY'][new Date().getDay()]

    console.log(weekday)


    var viewConformationEmails = "select " + weekday + " from clients";
    ibmdb.open(ibmdbconn, function(err, conn) {
        if (err) return console.log(err);
        conn.query(viewConformationEmails, function(err, rows) {
            if (err) {
                console.log(err);
                var today = new Date();
                var time = today.getMinutes() + " " + today.getHours() + " * " + "* " + "*"
                var errorJob = new cronJob(time, function() {
                    client.messages.create({
                        to: "1234567890",
                        from: '12055578708',
                        body: 'Error with your code: ' + err
                    }, function(err, data) {});
                }, null, true);
            }


            //note: when you're testing, Monday = day 1
            for (let i = 0; i < rows.length; i++) {
                let todaysColumn = rows[i][weekday];
                //userInfoString is the variable for splitting the string into 4 parts
                let userInfoString = todaysColumn.split('|');
                // console.log(userInfoString)
                //userTextString is the string that holds the value of (ex) 01 11 * * 1
                const userTextString = userInfoString[0]
                //userPhoneNumber gets phone number from finalSessionString
                const userPhoneNumber = userInfoString[1]
                //userNameString is getting the name of the person training
                const userNameString = userInfoString[2]
                //trainerNameString is getting the name of the trainer
                const trainerNameString = userInfoString[3]

                let timeSplit = todaysColumn.split(' ')
                let minute = timeSplit[0]
                console.log(minute)
                let today = new Date();
                    
                    if (Math.abs(today.getMinutes() - Number(minute)) <= 5) {
                        client.messages.create({
                                to: userPhoneNumber,
                                from: '12055578708',
                                body: 'hello ' + userNameString + ', \nYour training session just finished with ' + trainerNameString
                            }, function(err, data) {
                                if (err) {
                                    console.log("err: " + err)
                                }
                                console.log(data)
                            });
                    } else {
                        console.log("not working")
                    }

            }
            conn.close(function() {
                // console.log("closed the function /login");
            });
        });
    });
}, null, true)

now, let me explain. my cronjob runs every 5 minutes, querying the database, which the returns all the rows for the date today. it returns something like this:

56 15 * * 2|1234567890|Gianluca A|contact@inderatech.com

then i go and split it up using the .split you see at the beginning of the loop. I then do logic to see if the time returned from the db was in the last 5 minutes of the current time.

It does this successfully. Now, the problem is, it sends the texts message, but it sends it an infinite amount of times. I just need it to send 1 time. How can i fix this?

Answer 1

The cron expression has 6 total elements so the first is seconds. You have a * so you've set it to run every second during the fifth minute of the hour so it will run 60 times in a row.

The cron expression for "every 5 minutes" is */5 * * * * (note the slash, and 5 not 6 elements in the expression).

Answer 2

'rows.length' 的值是多少？