I need to increment the counter field as long as it's less than 500 otherwise reset the counter to zero.
Here is my snippet:
StudentInfo.findOneAndUpdate(
{ studId: SID },
**{ $inc: { counter: 1 } },**
(err, studInfo) => {
if (err || !studInfo) {
console.log(err);
} else {
console.log(${JSON.stringify(studInfo));
}
},
);
How can I do it in a single update call?
You can do it with Aggregation framework:
$cond with $lt - To check if the current value of the counter is less than 500$sum - To increase the current value of the counter by 1 if the condition is truedb.collection.update({
"key": 1
},
[
{
"$set": {
"counter": {
$cond: {
if: {
$lt: [
"$counter",
500
]
},
then: {
$sum: [
"$counter",
1
]
},
else: 0
}
}
}
}
],
{
"multi": false,
"upsert": false
})