I have a table_1 that has column dob which has datatype nvarchar(max). Now I want to check every date whether it is in datetime format or not.
The dates which are in datetime format should be copied to table_2 that has column with a datatype of datetime.
Any help how can I do this?
If you are using SQL Server 2012 or later, then TRY_CONVERT can help here:
SELECT *
FROM yourTable
WHERE TRY_CONVERT(datetime, dob) IS NULL;
This would return every record from your table where the dob text field is in some format which SQL Server cannot natively convert to a datetime.
This will insert all the strings can be converted into Table_2
INSERT INTO Table_2 (DateTimeColumn)
SELECT dob
FROM Table_1
WHERE TRY_CAST(dob AS DATETIME) IS NOT NULL;
It is a very bad habit to store datetime values in a string. The reason why: Date-Time formats differ around the world and depend on your system's culture settings. Even worse, some format depend on a given language. Try this out:
SET LANGUAGE ENGLISH; --try with GERMAN to see the effect on "Decemeber"
SET DATEFORMAT ymd; --try with "ydm" or "dmy"
DECLARE #tbl TABLE(dob NVARCHAR(MAX));
INSERT INTO #tbl VALUES('blah') --just a wrong value
,('20201231') --ISO, "unseparated YMD-format (see CONVERT with 112)
,('2020-12-31') --ISO8601
,('2020-31-12') --European with leading year
,('12-31-2020') --USA (see CONVERT with 110)
,('31-12-2020') --European (see CONVERT with 113)
,('31 December 2020') --language dependant (see CONVERT with 113), try with German "Dezember"
,('2020-02-30'); --Invalid, there's no 30th of February
SELECT t.dob --Your value
,[cast] = TRY_CAST(t.dob AS DATETIME) --CAST relies on the system's settings (might work on your machine but can break on a customer's machine
,[convert] = TRY_CONVERT(DATETIME, t.dob, 112) --CONVERT allows to use the style paramter, better than CAST, but more strict
,[parse] = TRY_PARSE(t.dob AS DATETIME USING 'en-US') --Parsing allows to mention the culture. You do not need to specify the language as a general setting
,[xmlCast] = CAST(t.dob AS XML).value('. cast as xs:date?','datetime') --Works below v2012, but can deal with ISO8601 only.
FROM #tbl t;
Play with the settings
You can use GERMAN instead of ENGLISH. The entry with December will not work any more. You can change the general date format to any combination of ymd and find, that some formats stop to work while others start to work.
TRY_CAST, TRY_CONVERT and TRY_PARSE will need a version of v2012 or higher.
If you are running an older system you should upgrade ( :-) ). The only chance with an older system is a XML hack, but this is very tightly bound to ISO8601.
Finally: For your next question, please try to add more information. State some of your input values, mention your RDBMS with version and try to set up a mockup with DDL and INSERT (look what I've done above).
Hint: Very dangerous...
Try to insert a value like 2020-05-06 and you will find, that some styles read this as the 5th of June, while others return the 6th of May. Returning wrong values is worse than returning NULL or throwing an error...
StayAtHome
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We just upgraded to SQL Server 2012 from 2005. While I'm a novice, something this simple couldn't be this difficult. I used to be able to pull data from a table based on the date vs date and time. As it now stands I have:
Select * from receipts_table where receipt_cancel_date = '2013-09-20'
before we upgraded this would work fine. How can I run this and actually get the desired results as I know there's receipts with a cancel date of 2013-09-20.
Thanx
If you are passing string for a date parameter, best format is ISO (yyyymmdd) format. Otherwise even though your string work in some servers it might not work in another depending on the culture of the server. ISO format is culture independent.
Also remove the time part from receipt_cancel_date column by converting it to a DATE (if DATETIME) for comparison purpose.
Try this:
Select * from receipts_table
where convert(date, receipt_cancel_date) = convert(date,'20130920')
Or use 120 style with your format:
Select * from receipts_table
where convert(date, receipt_cancel_date) = convert(date,'2013-09-20',120)
I know how to use CONVERT function in SELECT statement to change the format of the Date column:
SELECT
StationID
, CONVERT(varchar, [Date], 101) as Date
, Value
FROM my_table
But I was wondering if I can set the date format in general before running the SELECT statement, when I don't know the name of the date column in the following SELECT statement:
SELECT * from FROM my_table
Is any SET statement or other T-SQL that I can run before my SELECT statement so that I can change the Date format temporarily?
Thank you
No.
In particular, any date columns which you select are not actually formatted at all, but are instead returned down the wire as an actual piece of date data in a binary "format" which is used for dates. If you are seeing them formatted, it's because your client (either management studio or some other tool) is converting them to strings to display.
When you use SELECT *, there is obviously no way to tell SQL Server to do any conversions on any particular columns, so the data is going to be returned in whatever the data types of the underlying query returns. So regardless of whether your data types are really date or not, no manipulation is going to happen at that point anyway.
I'm pretty sure there's no way to do what you're asking. However, there are ways to format the date string when you output it using your programming language.
In a SQL Server 2000 DB, I have a table which holds string representations of Oracle DB dates. They are formatted like "16-MAY-12". I need to convert these to datetime. I can not seem to find a conversion style number that matches, nor can I find a function that will allow me to specify the input format. Any ideas?
This seems to work for me:
SELECT CONVERT(DATETIME, '16-MAY-12');
You can also try using TO_CHAR() to convert the Oracle values to a more SQL Server-friendly format (best is YYYYMMDD) before pulling them out of the darker side.
Follow Aaron's advice and cast to string on the Oracle side and then did a check/recast on the MS SQL side. See example below:
;WITH SOURCE AS (
SELECT * FROM openquery(lnk,
'SELECT
TO_CHAR(OFFDATE , ''YYYY-MM-DD HH24:MI:SS'') AS OFFDATE,
FROM
ORACLE_SOURCE')),
SOURCE_TRANSFORM AS
(
SELECT
CASE
WHEN ISDATE(OFFDATE) = 1 THEN CAST(OFFDATE AS DATETIME)
ELSE NULL END AS OFFDATE
FROM
SOURCE
)
SELECT * FROM SOURCE_TRANSFORM
As SQL Server returns timestamp like 'Nov 14 2011 03:12:12:947PM', is there some easy way to convert string to date format like 'Y-m-d H:i:s'.
So far I use
date('Y-m-d H:i:s',strtotime('Nov 14 2011 03:12:12:947PM'))
SQL Server's TIMESTAMP datatype has nothing to do with a date and time!
It's just a hexadecimal representation of a consecutive 8 byte integer - it's only good for making sure a row hasn't change since it's been read.
You can read off the hexadecimal integer or if you want a BIGINT. As an example:
SELECT CAST (0x0000000017E30D64 AS BIGINT)
The result is
400756068
In newer versions of SQL Server, it's being called RowVersion - since that's really what it is. See the MSDN docs on ROWVERSION:
Is a data type that exposes automatically generated, unique binary numbers within a database. rowversion is generally used as a mechanism
for version-stamping table rows. The
rowversion data type is just an incrementing number and does not
preserve a date or a time. To record a date or time, use a datetime2
data type.
So you cannot convert a SQL Server TIMESTAMP to a date/time - it's just not a date/time.
But if you're saying timestamp but really you mean a DATETIME column - then you can use any of those valid date formats described in the CAST and CONVERT topic in the MSDN help. Those are defined and supported "out of the box" by SQL Server. Anything else is not supported, e.g. you have to do a lot of manual casting and concatenating (not recommended).
The format you're looking for looks a bit like the ODBC canonical (style = 121):
DECLARE #today DATETIME = SYSDATETIME()
SELECT CONVERT(VARCHAR(50), #today, 121)
gives:
2011-11-14 10:29:00.470
SQL Server 2012 will finally have a FORMAT function to do custom formatting......
The simplest way of doing this is:
SELECT id,name,FROM_UNIXTIME(registration_date) FROM `tbl_registration`;
This gives the date column atleast in a readable format.
Further if you want to change te format click here.
Using cast you can get date from a timestamp field:
SELECT CAST(timestamp_field AS DATE) FROM tbl_name
Works fine, except this message:
Implicit conversion from data type varchar to timestamp is not allowed. Use the CONVERT function to run this query
So yes, TIMESTAMP (RowVersion) is NOT a DATE :)
To be honest, I fidddled around quite some time myself to find a way to convert it to a date.
Best way is to convert it to INT and compare. That's what this type is meant to be.
If you want a date - just add a Datetime column and live happily ever after :)
cheers mac
My coworkers helped me with this:
select CONVERT(VARCHAR(10), <tms_column>, 112), count(*)
from table where <tms_column> > '2012-09-10'
group by CONVERT(VARCHAR(10), <tms_column>, 112);
or
select CONVERT(DATE, <tms_column>, 112), count(*)
from table where <tms_column> > '2012-09-10'
group by CONVERT(DATE, <tms_column>, 112);
"You keep using that word. I do not think it means what you think it means."
— Inigo Montoya
The timestamp has absolutely no relationship to time as marc_s originally said.
declare #Test table (
TestId int identity(1,1) primary key clustered
,Ts timestamp
,CurrentDt datetime default getdate()
,Something varchar(max)
)
insert into #Test (Something)
select name from sys.tables
waitfor delay '00:00:10'
insert into #Test (Something)
select name from sys.tables
select * from #Test
Notice in the output that Ts (hex) increments by one for each record, but the actual time has a gap of 10 seconds. If it were related to time then there would be a gap in the timestamp to correspond with the difference in the time.
for me works:
TO_DATE('19700101', 'yyyymmdd') + (TIME / 24 / 60 / 60)
(oracle DB)
Robert Mauro has the correct comment. For those who know the Sybase origins, datetime was really two separate integers, one for date, one for time, so timestamp aka rowversion could just be considered the raw value captured from the server. Much faster.
After impelemtation of conversion to integer
CONVERT(BIGINT, [timestamp]) as Timestamp
I've got the result like
446701117
446701118
446701119
446701120
446701121
446701122
446701123
446701124
446701125
446701126
Yes, this is not a date and time, It's serial numbers
Why not try FROM_UNIXTIME(unix_timestamp, format)?
I had the same problem with timestamp eg:'29-JUL-20 04.46.42.000000000 PM'. I wanted to turn it into 'yyyy-MM-dd' format. The solution that finally works for me is
SELECT TO_CHAR(mytimestamp, 'YYYY-MM-DD') FROM mytable;
I will assume that you've done a data dump as insert statements, and you (or whoever Googles this) are attempting to figure out the date and time, or translate it for use elsewhere (eg: to convert to MySQL inserts). This is actually easy in any programming language.
Let's work with this:
CAST(0x0000A61300B1F1EB AS DateTime)
This Hex representation is actually two separate data elements... Date and Time. The first four bytes are date, the second four bytes are time.
The date is 0x0000A613
The time is 0x00B1F1EB
Convert both of the segments to integers using the programming language of your choice (it's a direct hex to integer conversion, which is supported in every modern programming language, so, I will not waste space with code that may or may not be the programming language you're working in).
The date of 0x0000A613 becomes 42515
The time of 0x00B1F1EB becomes 11661803
Now, what to do with those integers:
Date
Date is since 01/01/1900, and is represented as days. So, add 42,515 days to 01/01/1900, and your result is 05/27/2016.
Time
Time is a little more complex. Take that INT and do the following to get your time in microseconds since midnight (pseudocode):
TimeINT=Hex2Int(HexTime)
MicrosecondsTime = TimeINT*10000/3
From there, use your language's favorite function calls to translate microseconds (38872676666.7 µs in the example above) into time.
The result would be 10:47:52.677
Some of them actually does covert to a date-time from SQL Server 2008 onwards.
Try the following SQL query and you will see for yourself:
SELECT CAST (0x00009CEF00A25634 AS datetime)
The above will result in 2009-12-30 09:51:03:000 but I have encountered ones that actually don't map to a date-time.
Not sure if I'm missing something here but can't you just convert the timestamp like this:
CONVERT(VARCHAR,CAST(ZEIT AS DATETIME), 110)