Im using SQLite and trying to get my date into a blackberry datetime field.
in the DB its stored as string in format:
yyyy-MM-dd HH:mm
e.g. : 2012-02-01 15:45
But the field wants it as a Long.
date - The initial date value for this field. This is the number of milliseconds since midnight on January 1, 1970. To create an empty date field, set this parameter to Long.MIN_VALUE. This method will then remove the date value from this field, setting it to null.
And then convert it back again.
Check following code:
// conversion - string to long
long dateLong = HttpDateParser.parse("2012-04-17 16:09");
// conversion - long to string
Date dateObject = new Date(dateLong);
String dateStr = (new SimpleDateFormat("yyyy-MM-dd HH:mm")).format(dateObject);
Related
I am new to DynamoDB. I wish to create a table which using DeviceID as the hash key, Timestamp as my range key and some data.
{ DeviceID: 123, Timestamp: "2016-11-11T17:21:07.5272333Z", X: 12, Y: 35 }
In SQL, we can use datetime type for Timestamp, but in DynamoDB there is none.
What data type should I use? String? Number?
For the chosen data type, what kind of timestamp format should I write in? ISO format (e.g: 2016-11-11T17:21:07.5272333Z) or epoch time (e.g: 1478943038816)?
I need to search through the table through a range of time, e.g: 1/1/2015 10:00:00am until 31/12/2016 11:00:00pm
The String data type should be used for Date or Timestamp.
You can use the String data type to represent a date or a timestamp.
One way to do this is by using ISO 8601 strings, as shown in these
examples:
2016-02-15
2015-12-21T17:42:34Z
20150311T122706Z
DynamoDB Data type for Date or Timestamp
Yes, the Range queries are supported when the date is stored as String. The BETWEEN can be used on FilterExpresssion. I have got the items in the result using the below filter expressions.
FilterExpression without time:-
FilterExpression : 'createdate between :val1 and :val2',
ExpressionAttributeValues : {
':hkey' : year_val,
':rkey' : title,
":val1" : "2010-01-01",
":val2" : "2010-12-31"
}
FilterExpression with time:-
FilterExpression : 'createdate between :val1 and :val2',
ExpressionAttributeValues : {
':hkey' : year_val,
':rkey' : title,
":val1" : "2010-01-01T00:00:00",
":val2" : "2010-12-31T00:00:00"
}
Database Values:-
Format 1 - with timezone:
{"Item":{"createdate":{"S":"2010-12-21T17:42:34+00:00"},"title":{"S":"The Big New Movie 2010"},"yearkey":{"N":"2010"},"info":{"M":{"rating":{"N":"0"},"plot":{"S":"Nothing happens at all."}}}}}
Format 2 - without timezone:-
{"Item":{"createdate":{"S":"2010-12-21T17:42:34Z"},"title":{"S":"The Big New Movie 2010"},"yearkey":{"N":"2010"},"info":{"M":{"rating":{"N":"0"},"plot":{"S":"Nothing happens at all."}}}}}
Data type depends on your requirements.
You may use String using ISO format or Number using epoch format.
The advantage of ISO format (String) is human readability however DynamoDB does not support Time To Live (TTL) for this format. All filters work such as 'between' and 'range' as explained by notionquest.
Time To Live (TTL) for DynamoDB allows you to define when items in a table expire so that they can be automatically deleted from the database.
The advantage of using epoch format (Number) is that you can use the TTL feature and all filters.
TLDR;
Epoch format (Number type) - Can use Time To Live
ISO format (String type) - Cannot use Time To Live but is more human readable
for me to be able to filter out results when sending a query request, I used epoch format for DateTime, it is more efficient than using string.
imagine these scenarios: last 31 days, last 24 hours, ... again all is possible using the string format since it also has begins_with operator(please check 3rd example in below link on AWS doc) but numeric values are much more efficient in terms of performance while sorting(comparing) & calculation.
https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Query.html#Query.KeyConditionExpressions
it is easy to convert date-time to epoch format
Javascript:
var date = new Date();
var epoch = date.getTime();
// converting back to date-time
var initial_date = new Date(epoch);
C#
var date = DateTime.UtcNow;
var epoch = new DateTimeOffset(date).ToUnixTimeSeconds();
// converting back to date-time
var initial_date = DateTimeOffset.FromUnixTimeSeconds(epoch);
Python
import time
epoch = time.time()
# converting back to date-time
initial_date = time.gmtime(epoch )
The Number data type OR the String data type
can be used for Date or Timestamp - not just String as the Accepted Answer on this Question incorrectly singles out while ignoring Number.
You can use the number data type to represent a date or a timestamp. One way to do this is by using epoch time—the number of seconds since 00:00:00 UTC on 1 January 1970. For example, the epoch time 1437136300 represents 12:31:40 PM UTC on 17 July 2015.
For more information, see http://en.wikipedia.org/wiki/Unix_time.
...
You can use the String data type to represent a date or a timestamp. One way to do this is by using ISO 8601 strings, as shown in these examples:
2016-02-15
2015-12-21T17:42:34Z
20150311T122706Z
For more information, see http://en.wikipedia.org/wiki/ISO_8601.
DynamoDB Data type for Date or Timestamp
I've got 1 model.DateTime value (which is I'm getting from Database) and I want to represent model DateTime which is end time, and DateTime.Now as now time.
I want to format subtract of that 2 DateTime-s as a specific String format "dd:hh:mm:ss".
In your ASP .Net view page you can open razor block and you can calculate difference between 2 variables that are DateTime type.
#{
DateTime end = (DateTime)item.close_date_time;
DateTime now = DateTime.Now;
TimeSpan diff = end.Subtract(now);
}
Then you can simply convert TimeSpan diff to string:
#diff.ToString(#"dd\:hh\:mm\:ss")
And by that I've solved time difference and to format it to specific string.
EDITED
Simply you can do this:
DateTime CurrentDateTime = DateTime.Now;
item.duration.Subtract(CurrentDateTime).ToString(#"dd\:hh\:mm\:ss");
Hope this will help
I want to change datetime format so that first of all I got datetime and after that I have convert it to string with different format. Now I want to again convert this into datetime format but this gives an error, invalid date time. My code is:
DateTime startDT2 = DateTime.newInstance(selectedDate.addDays(1), initialEndTime);
system.debug('select dt2>>>'+ startDT2); **output**=2014-12-09 8:00:00
String myDate = startDT2.format('M/d/yyyy h:mm a');
system.debug('select mydate>>>'+ myDate); **output**=12/9/2014 1:00 AM
Datetime dt = Datetime.valueOf(myDate);
system.debug('date_string >>>'+ dt); **output**=invalid date/time
How to solve my problem?
From the documentation of Datetime.valueOf():
The specified string should use the standard date format “yyyy-MM-dd
HH:mm:ss” in the local time zone.
You can't use 12/9/2014 1:00 AM string and convert it to Datetime.
If the users locale is English (United States) then you can use the DateTime.parse(string) method:
Constructs a Datetime from the String datetime in the local time zone and in the format of the user locale.
Example
This example uses parse to create a Datetime from a date passed in as a string and that is formatted for the English (United States) locale. You may need to change the format of the date string if you have a different locale.
Datetime dt = DateTime.parse('10/14/2011 11:46 AM');
String myDtString = dt.format();
system.assertEquals(myDtString, '10/14/2011 11:46 AM');
Incidentally, the Salesforce StackExchange site is a great place to ask Salesforce specific questions.
I'm new to coding in asp.net and I'm struggling to format the date I've managed to pull from our CRM content pages' live date. I've wrote the following code that manages to pull and display the date the page was created:
TheDate = DR["LiveDate"].ToString();
But it formats the date and time like this:
13/11/2012 00:00:00
How can I modify my above code to just display the date like so:
Tuesday, 13 November 2012
Or, just without the time
13/11/2012
Thanks,
I assume that DR is a DataRow, isn't it?
If DR["LiveDate"] is already a DateTime column don't convert it to a localized string via ToString. Just cast it accordingly, for example via Field extension method:
DateTime dt = DR.Field<DateTime>("LiveDate");
If it's not a DateTime but a string you have to parse it to DateTime:
DateTime dt = DateTime.Parse(DR.Field<String>("LiveDate"));
If you want Tuesday, 13 November 2012 as result use:
string result = dt.ToString("dddd, dd MMMM yyyy", CultureInfo.InvariantCulture);
If you want 13/11/2012 use:
string result = dt.ToShortDateString();
or
string result = dt.ToString("d");
if your culture uses / as separator
otherwise
string result = dt.ToString("dd/MM/yyyy", CultureInfo.InvariantCulture);
Further informations: http://msdn.microsoft.com/en-us/library/8kb3ddd4(v=vs.110).aspx
for your second question, try
TheDate = DR["LiveDate"].ToString("dd/MM/yyyy")
I have a date column in my mysql db which stores
1999-03-30
as the date.
Using webservices when i extract the value by following code
DOB = Convert.ToDateTime(reader["DOB"]),
The output on the screen is
/Date(922732200000)/
How to get 1999-03-30 and what is this value /Date(922732200000)/...
The easiest way to handle dates in mysql is to use UNIX TIMESTAMP to store and retrieve dates.
For example:
The query for inserting date should be:
string query="insert into myTable(name,date) values ("StackOverflow",unix_timestamp('yyyy-mm-dd HH:mm:ss')";
eg. If you want to enter the current datetime, this query can be re-Written as:
string query="insert into myTable(name,date) values ("StackOverflow",unix_timestamp(current_timestamp)";
and when you retrive the data from your table, the query should be:
string queryToretrivedata="select name, from_unixtime(date) as DOB from myTable";
While the MySqlreader reads the data, the statement in your function should be:
DateTime DOB= Convert.ToDateTime(reader["DOB"].ToString());
Also, if you want to convert this dateTime into string you can use
string DateInString==DOB.ToString("yyyy-MM-dd HH:mm:ss"); //For 24 hour Format
string DateInString==DOB.ToString("yyyy-MM-dd hh:mm:ss tt"); //For 12 Hour format