I am using Node for fetching data from MySQL. In database, i got record like : 2013-08-13 15:44:53 . But when Node fetches from Database , it assigns value like 2013-08-19T07:54:33.000Z.
I just need to get time format as in MySQL table. Btw ( My column format is DateTime in MySQL)
In Node :
connection.query(post, function(error, results, fields) {
userSocket.emit('history :', {
'dataMode': 'history',
msg: results,
});
});
When retrieving it from the database you most likely get a Date object which is exactly what you should work with (strings are only good to display dates, but working on a string representation of a date is nothing you want to do).
If you need a certain string representation, create it based on the data stored in the Date object - or even better, get some library that adds a proper strftime-like method to its prototype.
The best choice for such a library is moment.js which allows you to do this to get the string format you want:
moment('2013-08-19T07:54:33.000Z').format('YYYY-MM-DD hh:mm:ss')
// output (in my case on a system using UTC+2 as its local timezone):
// "2013-08-19 09:54:33"
However, when sending it through a socket (which requires a string representation) it's a good idea to use the default one since you can pass it to the new Date(..) constructor on the client side and get a proper Date object again.
Related
I'm new to firebase and currently I'm still trying to learn how to get the latest children node based in this RTDB. My nodeMCU will send new data periodically so I'm trying to get the latest node when its added and the value of that node. Can you provide with a sample code for me to understand better? And if possible please explain like I'm 5. Thank you and have a good day.
From what I understand you have an Arduino module that is going to be constantly introducing data into your database.
What you want is to be able to read the value shown in the image as MQ7 every time a new value is added.
If this is the case there are different ways to obtain it.
The first and most common one would be to use the firebase Child Added event. With this event you can handle the data entered every time there is an addition to the reference to the database.
Using this event you would have a set of all the values entered in your reference and with each addition automatically (In Real Time) this set would be updated.
Taking your image as an example, the query code would be something like this (JS):
dbRef.child("Sensor MQ7").on("child_added", (snap) => {
for (i in snap.val()) {
const value_MQ7 = snap.child(i).child("MQ7").val()
// Do what you want with the value
console.log(value_MQ7)
}
})
If you don’t want to have that set with all the values entered in your reference, the best option would be a new function that returns only the value you are requesting, that is, a function that returns the MQ7 value of the last object entered in your reference sensor MQ7.
The query code would be something like this (JS):
const query = dbRef.child("Sensor MQ7").orderByKey().limitToLast(1);
query.get().then((snap) => {
for (i in snap.val()) {
// Do what you want with the value
const value_MQ7 = snap.child(i).child("MQ7").val()
console.log(value_MQ7)
}
})
This is about a different date-time recorded in mongoDb via Node.js.
e.g. the date time recorded is 2022-02-01T13:32:01.967Z,
the actual time is 19:02 for the same date.
Looks like it has recorded GMT. This code will be eventually run on a VPS based in my country. However, at the moment I am running the code on localhost.
below is the code in Node.js
/// part of a controller method
const xDate = new Date();
console.log('new Date()', xDate);
// output: 2022-02-01T13:32:01.967Z, actual time 19:02 on same date
candidate.history.push({
actionDate: xDate,
userId: user.acctId,
userName: user.userName,
remarks: 'bla bla bla'
})
await candidate.save();
Any idea how to correct it? In Angular we can set the input field to datetime-local type to save the date/time without timezone. Can we do something similar in Node.js /mongodb? How do I get the correct time stored in mongo?
I have read that MongoDB always stores the timestamp in UTC. Is there any way this can be handled application-wide to handle all date values recd from Mongo in both the below cases:
at Node.js levelfor performing some date calculations based on date value recd from Angular?
At Angular level for date values recd from Node(as it is from Mongo)
I got timestamp in Firebase Functions with
admin.database.ServerValue.TIMESTAMP
However, when I pass it as a string, it becomes [object object]
I saved it in Firebase Realtime database and when I checked it from console I saw 1505298866520 which I think it is milliseconds since UNIX epoch.
Do you know how can I get string from it or how can I do time calculations with it? Or what type of object TIMESTAMP returns?
The firebase.database.ServerValue.TIMESTAMP or admin.database.ServerValue.TIMESTAMP hold the following object {.sv: "timestamp"}. This is a specific firebase-database object. That tells the server it should use the server's UNIX-time when an object is added to the database.
That is the reason you can not use it as a date object in javascript.
If you use admin.database.ServerValue.TIMESTAMP on the server via cloud functions it should represent the same as new Date().getTime()
So, a quick overview of what I'm doing:
We're currently storing events to Azure Table storage from a Node.js cloud service using the "azure-storage" npm module. We're storing our own timestamps for these events in storage (as opposed to using the Azure defined one).
Now, we have coded a generic storage handler script that for the moment just stores all values as strings. To save refactoring this script, I was hoping there would be a way to tweak the query instead.
So, my question is, is it possible to query by datetime where the stored value is not actually a datetime field and instead a string?
My original query included the following:
.where( "_timestamp ge datetime'?'", timestamp );
In the above code I need to somehow have the query treat _timestamp as a datetime instead of a string...
Would something like the following work, or what's the best way to do it?
.where( "datetime _timestamp ge datetime'?'", timestamp );
AFAIK, if the attribute type is String in an Azure Table, you can't convert that to DateTime. Thus you won't be able to use .where( "_timestamp ge datetime'?'", timestamp );
If you're storing your _timestamp in yyyy-MM-ddTHH:mm:ssZ format, then you could simply do a string based query like
.where( "_timestamp ge '?'", timestamp );
and that should work just fine other than the fact that this query is going to do a full table scan and will not be an optimized query. However if you're storing in some other format, you may get different results.
I'm working with SailsJS and MongoDB and I have an API that has two models and I want to store Date and Time separately but as in the official documentation said it doesn't have a typeof Time attribute, just Date and DateTime. So, I'm using DateTime to store Time values.
I send the values in the request to be stored in the database, I have no problem to store dates, I just send a value like:
2015-12-16
and that's it, it is stored in the table with no problem, but when I want to store a Time value like:
19:23:12
it doesn't works. The error is:
{
"error": "E_VALIDATION",
"status": 400,
"summary": "1 attribute is invalid",
"model": "ReTime",
"invalidAttributes": {
"value": [
{
"rule": "datetime",
"message": "`undefined` should be a datetime (instead of \"19:23:12\", which is a string)"
}
]
}
}
So, any idea how to send the time value to be stored in a DateTime attribute?
I also have tried to send it in different formats like:
0000-00-00T19:23:12.000Z
0000-00-00T19:23:12
T19:23:12.000Z
19:23:12.000Z
19:23:12
But any of them works fine.
Also I was thinking to store both values (Date and Time) in plain text, I mean typeof String attributes. But I need to make some queries and I don't know if it will affect the performance with the waterline ORM.
Please any kind of help will come in handy.
Thanks a lot!
You have two options here. The best would be to simply store the date and time as a datetime and parse them into separate values when you need to use them. MongoDB will store this in BSON format and this will be the most efficient method.
Otherwise, you could use string and create a custom validation rule as described in the Sails documentation.