How to get Current date using Poco ? (Only Date) No Time Stamp - c++11

Is there a way we get a Date only from Poco ? One way is to get the Poco DateTime stamp and truncate the Date, But is there any way which gives directly current Date ?
Like for example I am using like this to get Date
void getTimestamp(std::string &out_iTimestamp)
{
//Get the CurrentTimestamp
Poco::Timestamp t_oCurTimestamp;
Poco::DateTimeFormatter t_oFormatter;
string t_strDateTime;
t_oFormatter.append(t_strDateTime, t_oCurTimestamp, Poco::DateTimeFormat::ISO8601_FORMAT);
out_iTimestamp = t_strDateTime;
}
Now I am truncating the Date
std::string t_strDateTime;
std::string t_strDate;
getTimestamp(t_strDateTime);
//extract the only Date from DateTimeStamp
std::size_t found = t_strDateTime.find('T');
if (found != std::string::npos){
t_strDate = t_strDateTime.substr(0,found);
}
Any one know the simple way ?

As already answered here, use Poco::DateTimeFormatter with your own format:
Poco::DateTimeFormatter::format(date, "%d/%m/%Y");

Related

Laravel - different formats for date/time query

I am learning Laravel and I have some small problem on controllers - when I use DB, the query returns date time without timezone but if I use model, the query returns full datetime.
public function test($switch)
{
//return "YYYY-MM-DDThh:mm:ss.000000Z"
if ($switch) return Position::select('id','created_at')->orderBy('id')->get();
// return "YYYY-MM-DD hh:mm:ss"
return DB::table('positions')->select('id','created_at')->orderBy('id')->get();
}
Why? What I need to dof I want "YYYY-MM-DDThh:mm:ss.000000Z" on both cases?
Thanks for solution.
thanks for advice
You should use the DB::raw
The following statement will convert the datetime value created_at from +00:00 timezone to +10:00 timezone.
You can try this
return DB::table('positions')->select(DB::raw('id',CONVERT_TZ('created_at','+00:00','+10:00'))->orderBy('id')->get();
you can set your timezone that you wants to convert it
They are the same data, probably just different classes of date and you can always format your date. Laravel utilizes Carbon date library which is excellent and should be used primarily.
If you try to print out your date class with get_class() for Eloquent Position created_at, you probably got Carbon and DB::table('positions') created_at, you probably got DateTime and that's why the value looks different (but you still got the same date).
If you want to convert your DateTime to Carbon, you can do
$newDate = new \Carbon\Carbon($position->created_at)
Thanks Anurat,
I realized this fact shortly after sending the previous question.
... but there is another 'issue' - both times are my local time - time in "YYYY-MM-DDThh:mm:ss.000000Z" is not UTC time as I expected.
I changed my function:
public function test($switch = false)
{
$data = Position::selectRaw('id, created_at, UNIX_TIMESTAMP(created_at) unix')->orderBy('id')->get();
foreach ($data as $d) {
$conv = new \DateTime($d->created_at);
$d->conv = intval($conv->format('U'));
$d->diff = $d->conv - $d->unix;
}
return $data;
}
... and result is
0
id 1
created_at "2021-03-18T12:36:59.000000Z"
unix 1616067419
conv 1616071019
diff 3600
As you see, the difference is 1 hour (as my timezone offset). Where is a problem?
Thanks.

To extract the DateTime from the name of file(ex. "vga_20171201.txt") in U-SQL

I want to extract the filename string as a DateTime column.
The code for it as follows:
#data =
EXTRACT
...
filename_date DateTime
FROM "/input/vga_{filename_date}.txt"
USING Extractors.Tsv(skipFirstNRows:1);
filename = vga_20171201.txt
whenever i have used datatype as string or int, it's work for me.
You have to specify .net date format strings along with the virtual column name to get that behaviour, like this:
#data =
EXTRACT someData string,
filename_date DateTime
FROM "/input/vga_{filename_date:yyyy}{filename_date:MM}{filename_date:dd}.txt"
USING Extractors.Tsv(skipFirstNRows : 1);
I have a series of files that are named like 1601.gz to represent January of 2016. {date:yyMM}.gz or {date:yy}{date:MM}.gz don't seem to

How can i change timezone in neo4j?

I want to change default timezone from UTC to another timezone. How it will be possible? I tried
RETURN apoc.date.format(timestamp(),'ms', 'yyyy/MM/dd HH/mm/ss')
but it returns utc time on localhost.
Example answer:
RETURN apoc.date.format(timestamp(),'ms', 'yyyy/MM/dd HH:mm:ss',"Europe/Paris")
Method from the source:
public String format(final
#Name("time") Long time
,#Name(value = "unit", defaultValue = "ms") String unit
,#Name(value = "format",defaultValue = DEFAULT_FORMAT) String format
,#Name(value = "timezone",defaultValue = "") String timezone)
{
return time == null ? null : parse(unit(unit).toMillis(time), format, timezone);
}
The timezone parameter is further passed to Java TimeZone class constructor.
From Java documentation as to what it should contain -
the ID for a TimeZone, either an abbreviation such as "PST", a full
name such as "America/Los_Angeles", or a custom ID such as "GMT-8:00".
Note that the support of abbreviations is for JDK 1.1.x compatibility
only and full names should be used.
The source code of this project -
https://github.com/neo4j-contrib/neo4j-apoc-procedures/blob/3.3/src/main/java/apoc/date/Date.java
For more info, have a look at this article about dates in APOC
http://xclave.azurewebsites.net/2018/02/28/better-know-apoc-apoc-3-date-parse-format/

Extract only date part in a datetimein LINQ

We have some data in a DataTable and we are using the query like this to get what we need.
IEnumerable<Results> subResult = from query in datatable.AsEnumerable()
select new Results
{
Name = query.Field<string>("Name"),
Date = query.Field<DateTime?>("Date")
}
This above query returns what i need but date in full format (Ex: m/dd/yyyy hh:min:sec am/pm) but we need only date part of it(only mm/dd/yyyy need to be pulled in). When looked in the properties of this, couldn't find an implicit way to get it, please help me in getting this result. Thanks.
The DateTime class has all the properties you just mentioned. You should try to fix your display with the ToString("anyformatyouwant") formats.
What about this?
Date = query.Field<DateTime?>("Date").Date
This will give you just the date part:
IEnumerable<Results> sub-result= from query in datatable.AsEnumerable()
where new Results
{
Name = query.Field<string>("Name"),
Date = query.Field<DateTime?>("Date").Date
}
However if you just want to display the date somewhere (meaning you're not using this to do date grouping, etc. then I would just specify the display format in your UI layer.
AFAIK there is no Date Class in .net, if you want pure date you should write a Class for that, otherwise you can pull out the part as a string
DateTime.Now.Date.ToString("yyyy/MM/dd")
gives you the current date in string type, but if you get the .Date part it gives you a DateTime object which still has a time part showing AM 12:00:00:0 blah blah

How do I extract the created date out of a Mongo ObjectID

I'm using the Mongo shell to query my Mongo db. I want to use the timestamp contained in the ObjectID as part of my query and also as a column to extract into output. I have setup Mongo to create ObjectIDs on its own.
My problem is I can not find out how to work with the ObjectID to extract its timestamp.
Here are the queries I am trying to get working. The 'createdDate' field is a placeholder; not sure what the correct field is:
//Find everything created since 1/1/2011
db.myCollection.find({date: {$gt: new Date(2011,1,1)}});
//Find everything and return their createdDates
db.myCollection.find({},{createdDate:1});
getTimestamp()
The function you need is this one, it's included for you already in the shell:
ObjectId.prototype.getTimestamp = function() {
return new Date(parseInt(this.toString().slice(0,8), 16)*1000);
}
References
Check out this section from the docs:
Extract insertion times from _id rather than having a separate timestamp field
This unit test also demostrates the same:
mongo / jstests / objid6.js
Example using the Mongo shell:
> db.col.insert( { name: "Foo" } );
> var doc = db.col.findOne( { name: "Foo" } );
> var timestamp = doc._id.getTimestamp();
> print(timestamp);
Wed Sep 07 2011 18:37:37 GMT+1000 (AUS Eastern Standard Time)
> printjson(timestamp);
ISODate("2011-09-07T08:37:37Z")
This question is helpful to understand of how to use the _id's embedded timestamp in query situations (refers to the Mongo Extended JSON documentation). This is how it's done:
col.find({...,
'_id' : {'$lt' : {'$oid' : '50314b8e9bcf000000000000'}}
})
finds documents created earlier than the one that's given by oid. Used together with natural sorting and limiting you can utilize BSON _ids to create Twitter-like API queries (give me the last OID you have and I'll provide twenty more)
In python you can do this:
>>> from bson.objectid import ObjectId
>>> gen_time = datetime.datetime(2010, 1, 1)
>>> dummy_id = ObjectId.from_datetime(gen_time)
>>> result = collection.find({"_id": {"$lt": dummy_id}})
I think, ObjectId.from_datetime() - its a useful method of standard bson lib
Maybe other language bindings have alternative builtin function.
Source: http://api.mongodb.org/python/current/api/bson/objectid.html
To use the timestamp contained in the ObjectId and return documents created after a certain date, you can use $where with a function.
e.g.
db.yourcollection.find( {
$where: function() {
return this._id.getTimestamp() > new Date("2020-10-01")
}
});
The function needs to return a truthy value for that document to be included in the results. Reference: $where
Mongo date objects can seem a bit peculiar though. See the mongo Date() documentation for constructor details.
excerpt:
You can specify a particular date by passing an ISO-8601 date string with a year within the inclusive range 0 through 9999 to the new Date() constructor or the ISODate() function. These functions accept the following formats:
new Date("<YYYY-mm-dd>") returns the ISODate with the specified date.
new Date("<YYYY-mm-ddTHH:MM:ss>") specifies the datetime in the client’s local timezone and returns the ISODate with the specified datetime in UTC.
new Date("<YYYY-mm-ddTHH:MM:ssZ>") specifies the datetime in UTC and returns the ISODate with the specified datetime in UTC.
new Date(<integer>) specifies the datetime as milliseconds since the Unix epoch (Jan 1, 1970), and returns the resulting ISODate instance.

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