Oracle date time format - database

In the oracle table, the datetime value is stored like this:
44412,46854418982
What is this format? How can I convert it to DateTime format?

What is this format?
It looks like a number formatted using a comma as the decimal separator.
We have no way of knowing what it means beyond that; you should ask the developer who created the table what it is meant to represent or consult the design documentation for the database (assuming that they created some documentation).
We can possibly guess that it could be days since 1900-01-01 and if you have the sample data:
CREATE TABLE table_name (value) AS
SELECT 44412.46854418982 FROM DUAL;
Then you can convert it using:
SELECT value,
DATE '1900-01-01' + value As date_value
FROM table_name;
Which, with the NLS settings:
ALTER SESSION SET NLS_NUMERIC_CHARACTERS=',.';
ALTER SESSION SET NLS_DATE_FORMAT='YYYY-MM-DD HH24:MI:SS';
Outputs:
VALUE
DATE_VALUE
44412,46854418982
2021-08-06 11:14:42
However, you could just as easily pick any other epoch and any other time interval and use that:
SELECT value,
DATE '1970-01-01' + value * INTERVAL '1' HOUR As hours_since_1970,
DATE '1970-01-01' + value As days_since_1970,
DATE '2000-01-01' + value * INTERVAL '1' SECOND As seconds_since_2000
FROM table_name;
Which outputs:
VALUE
HOURS_SINCE_1970
DAYS_SINCE_1970
SECONDS_SINCE_2000
44412,46854418982
1975-01-25 12:28:06
2091-08-06 11:14:42
2000-01-01 12:20:12
db<>fiddle here

Related

SQL datetime compare

I want to get some values from my table an there are some conditions about its datetime columns.
I want to get all hotel values of a stated city from my table, which is named "LocalHotels". Also I should declare two DateTimevalues. First value should be less than or equal to hotel's value in "start" column, which is datetime data type. Second value should be greater than or equal to hotel's value in "deadline" column, which is datetime data type, either.
All datetime values in these two columns are inserted in German CultureInfo format.
When I stated query below, there are no problems;
string query = "SELECT * FROM LocalHotels WHERE city='LONDON' AND start <='5.12.2015 00:00:00' AND deadline >='8.12.2015 00:00:00' ORDER BY city";
However when I changed day value of DateTime values from one digit to two digits, as I stated in below;
string query "SELECT * FROM LocalHotels WHERE city='LONDON' AND start <='15.12.2015 00:00:00' AND deadline >='18.12.2015 00:00:00' ORDER BY city"
I got an SQLException which indicates;
The conversion of a varchar data type to a datetime data type resulted
in an out-of-range value.
Even though in Europe and everywhere in the world it makes perfect sense to use the month as the second of three items in the date. In the US and in this case, apparently, SQL's date time is MM.DD.YYYY, so you're going for the 15th month and 18th month
Therefore you should use
string query "SELECT * FROM LocalHotels WHERE city='LONDON' AND start <='12.15.2015 00:00:00' AND deadline >='12.18.2015 00:00:00' ORDER BY city"
or
string query "SELECT * FROM LocalHotels WHERE city='LONDON' AND start <='2015-12-15' AND deadline >='2015-12-18' ORDER BY city"
Try changing
15.12.2015 00:00:00
to
2015-12-15 00:00:00
and same format for the other date also.
You can view SQL Server's date and time format for yourself by running this query:
SELECT
GETDATE()
As you can see the format is YYYY-MM-DD HH:MM:SS.MMM. Stick to this and you won't run into any unexpected conversion errors.
EDIT
ISO 8601 is a standard date format. From MS Docs:
The advantage in using the ISO 8601 format is that it is an international standard with unambiguous specification. Also, this format isn't affected by the SET DATEFORMAT or SET LANGUAGE setting.
For this reason I would recommend it above all other formats. Examples:
2020-02-25
20200225
2020-02-25T18:37:00
SELECT CONVERT(char(10), GetDate(),126)
or
select convert(varchar,getDate(),112)
or
select replace(convert(varchar, getdate(), 111), '/','-')
Test out the queries above to get the date in the desired format (replace GetDate() with your date, or dateColumn).
As others pointed out you need the format YYYY-MM-DD.

display current date -1 in sybase

I am trying to display the previous day's date Sybase using a select query:
select dateadd(day,-1,convert(char(10), getdate(), 23))
this query displays as 2015-06-18 00:00:00.0
I expect the output to be 2015-06-18.
How can I get that?
Try select dateadd(day,-1,convert(Date, getdate(), 365))
Try select convert(char(10),dateadd(day,-1, getdate() ), 23 )
Dateadd expects a date parameter as the third argument. In your example you're feeding it a char(10) . Even though implicit conversion from Char->DateTime is supported in Sybase, I would not code to depend on it in this case.
Well, datetime is a binary type. How it is formatted for display is up to you.
getdate() returns a datetime representing the current date/time. And dateadd() returns a datetime or date value, depending on what it started with (in your case, that would be datetime). And when you run your select statement, it's getting converted to a string using the default format configured for your Sybase instance. Hence your results.
In a nutshell, you are:
Converting the datetime value to char(10) to get an ISO 8601 format date string (yyyy-mm-dd).
Converting that back to a datetime value (so the time component is start-of-day)
Subtracting one day.
The easiest way to get what you want (yesterday's date) is this:
dateadd(day,-1, convert(date,getdate()) )
Which, when formatted for display, will come out as something like (depending on the default format configured for your Sybase instance) yyyy-mm-dd.
Or it might come out like November 29, 2015. If you want to ensure that it is an ISO 8601 date representation, you'll need to be explicit about it and cast it a char or varchar, thus:
convert(char(10) , dateadd(day,-1, convert(date,getdate()) ) , 23 )
which leaves you with a char(10) value containing yesterday's date.
If your version of Sybase doesn't support date, you'll have to fall back to what you were doing, but something like this:
convert(char(10) , dateadd(day,-1, getdate() ) , 23 )
You are telling it to give you hh:mm:ss, so that's what you are getting.
The 23 inside the convert is the format code for yyyy-mm-ddTHH:mm:ss There is no code to get yyyy-mm-dd, the closest you can get is 105 (dd-mm-yy) or 110 (mm-yy-dd).
If you need yyyy-mm-dd, then you'll have to convert the date to a string(char or varchar), and truncate the parts you don't want.
Converting Datetime

Convert One Datetime format to another in SQL Server

I have a datetime2 format in my Database 2015-06-22 06:23:42.790. I need to convert this into the following format 22/06/2015 06:23:42.790.
Is it possible?
Here is one way to do this:
DECLARE #date DATETIME2 = '2015-06-22 06:23:42.790';
SELECT cast(convert(VARCHAR(10), cast(LEFT(#date, 10) AS DATE), 3) AS VARCHAR(10))
+ ' ' + substring(cast(#date AS VARCHAR(50)), 12, 12)
Query breakdown:
First part: take first 10 characters from your datefield and then convert it to date style 3 (dd/mm/yyyy).
Second part: Add a space between date and time.
Third part: cast your datefield as varchar and extract the time which should always start in the 12th position of your string.
Join them all together and there you have it! Hope this helps!
Don't try to convert the database layout. Year Month Day is how SQL server shows the date because it ignores any international date formats.
I notice you want it as 22/06/2015 are you in the UK ? In the USA it would be 06/22/2015 Not such a problem because it's obvious that the 22 is the day. But if the date was 05/06/2015 how would sql or anyone know what day or month you're talking about.
So, get in to the habit of working in the ISO format year month day.
You don't mention what programming language. When reading data out of the database youd read it into a datetime variable. That will convert the date correctly into whatever locale your user is using. Different languages have different ways of getting the date into a datettime variable.
If it's only for display-use you can convert to varchar with FORMAT() function:
DECLARE #tab TABLE
(
datevalue DATETIME2
)
INSERT INTO #tab VALUES(GETDATE())
SELECT datevalue,
FORMAT(datevalue,'dd/MM/yyyy hh:mm:ss.fff') as newformat
FROM #tab

Allow Search for Invalid Date stored as string - Is it recommended or not

I have two tables for an Entity - say Valid_Doc and Invalid_Doc. If document is valid, then all the data gets saved in Valid_Doc table.In case any of the attribute of document is invalid , it gets saved in Invalid_Doc.Due_Date is on of the column of both the tables. In Invalid_Doc , we are saving Invalid dates as string.
Suppose if user searches for documents through a SEARCH screen with following date
Due_Date - is after - 07/07/11,
Shall we show all the documents from both the tables.As Due_Date in Invalid_Doc table is string, there is no way we can compare the entered search date with the dates available in database in Invalid_Doc table.
Can someone please guide me whether to use DATEDIFF - i.e. need to convert the String date in DB to Date(millisecs) first and then do the comparison with the entered data.Doing this , there may be unpredictable results. So , shall we allow the user to search for Invalid doc through Date or NOT.
Select * FROM invalid_doc iil WITH (nolock) WHERE
CAST(Datediff(s, '19700101 05:00:00:000', iil.due_date) AS NUMERIC) *
1000
BETWEEN '1120501800000' AND '1120501800000'
Where '1120501800000' and '1120501800000' are Date converted in milliseconds.
Please suggest.
I would convert the dates in the database to a uniform string format using regex (eg. Q20011231Q) and also convert the query to the same format before searching.
This way you would have control on your data and can easily do comparisons
I continue as answer :)
As I don't know your language you handle the xml data I strongly suggest you validate you date befor you insert into your database.
It is not possible to enter a non valid data value into a datatime field.
if you have a data like 11/24/2011 and insert it, the datetime value always add the time itself.
Then you have eg. 11/24/20011 17:29:00 000 as value stored.
If you insert less then a date it might crash or if the value can be converted to a valid date, the missing parts will be replaced by "current date information".
So in fact you have to validate you string, convert it. Something like this:
-- #datestring <= somehow your string from xml
SET arithabort arith_overflow OFF
SET #date = CAST(#datestring AS DATETIME)
IF #date is NULL SET #date = GETDATE()
SET arithabort arith_overflow ON
You turn overflow error mode off, try convert and set default if it fails.
Or in MS SQL
IF ( ISDATE(#date_string) = 0 ) SET #date = GETDATE()
Hope this helps

Average a time value in SQL Sever 2005

I've got a varchar field in SQL Sever 2005 that's storing a time value in the format "hh:mm"ss.mmmm".
What I really want to do is take the average using the built in aggregate function of those time values. However, this:
SELECT AVG(TimeField) FROM TableWithTimeValues
doesn't work, since (of course) SQL won't average varchars. However, this
SELECT AVG(CAST(TimeField as datetime)) FROM TableWithTimeValues
also doesn't work. As near as I can tell, SQL doesn't know how to convert a value with only time and no date into a datetime field. I've tried a wide variety of things to get SQL to turn that field into a datetime, but so far, no luck.
Can anyone suggest a better way?
SQL Server can convert a time-only portion of a datetime value from string to datetime, however in your example, you have a precision of 4 decimal places. SQL Server 2005 only recognizes 3 places. Therefore, you will need to truncate the right-most character:
create table #TableWithTimeValues
(
TimeField varchar(13) not null
)
insert into #TableWithTimeValues
select '04:00:00.0000'
union all
select '05:00:00.0000'
union all
select '06:00:00.0000'
SELECT CAST(TimeField as datetime) FROM #TableWithTimeValues
--Msg 241, Level 16, State 1, Line 1
--Conversion failed when converting datetime from character string.
SELECT CAST(LEFT(TimeField, 12) as datetime) FROM #TableWithTimeValues
--Success!
This will convert valid values into a DATETIME starting on 1900-01-01. SQL Server calculates dates based on 1 day = 1 (integer). Portions of days are then portions of the value 1 (i.e. noon is 0.5). Because a date was not specified in the conversion, SQL Server assigned the value of 0 days (1900-01-01), which accommodates our need to average the time portion.
To perform an AVG operation on a DATETIME, you must first convert the DATETIME to a decimal value, perform the aggregation, then cast back. For example
SELECT CAST(AVG(CAST(CAST(LEFT(TimeField, 12) as datetime) AS FLOAT)) AS DATETIME) FROM #TableWithTimeValues
--1900-01-01 05:00:00.000
If you need to store this with an extra decimal place, you can convert the DATETIME to a VARCHAR with time portion only and pad the string back to 13 characters:
SELECT CONVERT(VARCHAR, CAST(AVG(CAST(CAST(LEFT(TimeField, 12) as datetime) AS FLOAT)) AS DATETIME), 114) + '0' FROM #TableWithTimeValues
Try this
AVG(CAST(CAST('1900-01-01 ' + TimeField AS DateTime) AS Float))
You really should store those in a datetime column anyway. Just use a consistent date for that part (1/1/1900 is very common). Then you can just call AVG() and not worry about it.
I used Cadaeic's response to get an answer I was looking for, so I thought I should share the code....
I was looking for a query that would average ALL my times together and give me an overall Turn Around Time for all approvals. Below is a nested statement that gives you the AVG TAT for individual id's and and when nested an overall TAT
SELECT
-- calculates overall TAT for ALL Approvals for specified period of time
-- depending on parameters of query
CONVERT(VARCHAR, CAST(AVG(CAST(CAST(LEFT(Tat_mins, 12) as datetime) AS FLOAT)) AS DATETIME), 108) + '0'
from
(
-- tat is for individual approvals
SELECT
dbo.credit_application.decision_status,
dbo.credit_application.application_id,
cast(dbo.credit_application.data_entry_complete as date) as'Data Entry Date',
cast(dbo.credit_application.decision_date as DATE) as 'Decision Date',
avg(datediff(minute, dbo.credit_application.data_entry_complete, dbo.credit_application.decision_date)) as 'TAT Minutes',
convert (char(5), DateAdd(minute, Datediff(minute,dbo.credit_application.data_entry_complete, dbo.credit_application.decision_date),'00:00:00'),108) as 'TAT_Mins'
FROM dbo.credit_application
where Decision_status not in ('P','N')
group by dbo.credit_application.decision_status,
dbo.credit_application.data_entry_complete,
dbo.credit_application.decision_date
--dbo.credit_application.application_id
)bb
How do you think to average on datetime?
I guess that you need to GROUP BY some period (Hour?), and display Count(*)?
SQL Server stores datetime data as 2 4-byte integers, hence a datetime take 8 bytes. The first is days since the base date and the second is milliseconds since midnight.
You can convert a datetime value to an integer and perform mathematical operations, but the convert only returns the "days" portion of the datetime value e.g. select convert(int,getdate()). It is more difficult to return the "time" portion as an integer.
Is using SQL Server 2008 an option for you? That version has a new dedicated time data type.
Thanks, Andy.
I'd work out the difference between all of the dates and an arbitrary point (01/01/1900), average it and then add it back on to the arbitrary point.

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