Parse a date from unformatted text in SQL - sql

I'm trying to figure out an elegant way to get a date from a text column that has data like this "YYYYMMDD"...so we might see "20060508" as a value in the column, which I would like to be able to return from a query as a date (May 8, 2006).
I'm sure I can hack something together given enough time, but the approaches I'm thinking of seem pretty kludgy, and I suspect there's a way this can be elegantly done in a single query.
Any suggestions?

This is already a valid date - ISO-8601 format - just use:
SELECT CAST('20060508' AS DATETIME)
or alternatively:
SELECT CONVERT(DATETIME, '20060508', 112)
and that should do just fine!
In order to get your "May 08, 2006" display, do another convert into varchar, using the date convert style 107:
SELECT CONVERT(VARCHAR(25), CAST('2006-05-08' AS DATETIME), 107)
See here for more information on casting & converting in MS SQL

select cast('20060508' as datetime) AS MyDate
gives you this result...
MyDate
-----------------------
2006-05-08 00:00:00.000
See here for more information on casting & converting in MS SQL.
If you're trying to achieve a specific format (May 8, 2006) - you should consider just returning the column as a datetime value, and letting whatever is going to display that value to the end user (website, client app, report, etc) do the formatting. If you format it at the query, you'll be returning a string, which will make it harder to swap out formats from your front end in the future. If you want to do it in SQL - check out format 107 in the link above.

No sweat, just CONVERT it. Style "112", or ISO would handle your example case.
SELECT CONVERT(datetime,'20060508',112)
returns
----------------------- 2006-05-08 00:00:00.000
(1 row(s) affected)

try:
SELECT REPLACE(CONVERT(varchar(30),CONVERT(datetime, '20060508'),107),' 0',' ')
output:
-------------------
May 8, 2006
(1 row(s) affected)

Related

Convert dd-mm-yyyy to mm/dd/yyyy

I have a varchar(200) column called Submit_Date and I am trying to convert it to MM/DD/YYYY format. When I do that I get the following error:
Msg 242, Level 16, State 3, Line 1The conversion of a varchar data type to a datetime data type resulted in an out-of-range value.
Sample Data of the table is:
Submit_Date
-----------------------
27-09-2013 16:15:00 CST
30-09-2013 16:30:24 CST
27-09-2013 10:03:46 CST
I tried the following:
Select Convert(datetime,Submit_date,101) from dbo.Tickets
You've committed about 15 cardinal sins about date/time here. First, the quick answer:
DECLARE #x VARCHAR(200);
SELECT #x = '27-09-2013 16:15:00 CST'
SELECT CONVERT(CHAR(10),CONVERT(DATETIME,LEFT(#x,10),105),101);
Next:
Why on earth are you storing date/time data in a varchar(200) column? You are aware that anyone can insert values like '09-27-2013' or '465-32-207floob' in there, right? If you need time zone information you can look at the DATETIMEOFFSET data type (but note that it is not DST-aware).
Why are you storing a regional format like dd-mm-yyyy? If the first value were 07-11-2013 I'd have to guess if you meant July 11 or November 7. If you're not going to do it right and use a proper date/time data type, why use a string format that makes people guess? You are much better off with a format that is unambiguous, such as yyyy-mm-ddThh:mm:ssZ.
Similarly, why are you outputting a different regional format like mm/dd/yyyy? If you output '05/06/2013' are you 100% confident that everyone in your audience will know you meant May 6 and not June 5? Your output should be unambiguous as well. If you absolutely must format in some regional and ambiguous format, use the string formatting capabilities of your client. For example, C# has .ToString() and .Format() which are much more powerful and efficient in presenting dates with string formats that T-SQL will ever be.
try the following SQL query to achieve the expected result:
SELECT convert(varchar, convert(date, '27-09-2013 16:15:00', 105), 101)

Why this Query is returning different results for different date formats?

I have a table named book_data with batch_dt as column name of type varchar in sql server.
when I pass the query
SELECT DISTINCT batch FROM book_data
it gives me the following results
batch_dt
-------------
2012-10-31
-------------
2012-11-01
-------------
2012-11-02
-------------
2012-11-03
-------------
.
.
.
Now what I am doing is getting the total count of records between two dates. Fairly a simple query.
SELECT COUNT(*) FROM book_data WHERE CONVERT(varchar(12),CONVERT(datetime,batch_dt),101) BETWEEN '11/02/2012' and '10/31/2012'
the result is
112
and just by changing the month from 02 to 2 the query gives me 218 results
SELECT COUNT(*) FROM book_data WHERE CONVERT(varchar(12),CONVERT(datetime,batch_dt),101) BETWEEN '11/2/2012' and '10/31/2012'
why this different behaviour?
Use CAST(batch_dt AS DATE) instead, and pass the date in a language neutral manner, in the format YYYYMMDD. This way it will be comared as a date not as a varchar:
SELECT COUNT(*)
FROM book_data
WHERE CAST(batch_dt AS DATE)
BETWEEN '20121102' and '20121130'
But, this is not safe, if there was any value in barch_dt in a wrong format, you will get a casting error. In this case you can add ISDATE(batch_dt) = 1 to ensure that it is a valid data time. But it is better to make this column of datatype DateTime.
Another thing to note: is that BETWEEN is asymmetric in SQL Server, meaning that BETWEEN '11/02/2012' and '10/31/2012' is evaluated as:
DATE >= '11/02/2012'
AND
DATE <= '10/31/2012'
which will never be true, the reason it works for you is that the dates were be compared as strings not as a dates. But you have to keep it like BETWEEN the small value and the biggest value.
You compare string with BETWEEN. If you do so you need to make sure that you compare in the correct order => YYYYMMDD MM:SS would be a correct order.
If you can, add columns with type datetime and store real date time values in your database. If you can not do that you can split up the values and build a date value yourself. This is much slower then just use a CONVERT() or CAST() but you can make sure that it works even with wrong date-strings.
You can use PATINDEX(),LEFT(),RIGHT() keywords to get the values you need or you use a split() function (you can find many version google it, e.g. https://codereview.stackexchange.com/questions/15125/sql-server-split-function-optimized). If you use the split function, then split by / and then get year, month, day from the positions.
But best would be still to have correct datetime values stored in your db.
You get this different behavior because you don't compare the dates but the strings/varchars.
For a Date (or DateTime), 10/2/2012 is the same as 10/02/2012.
But for string, these values are (of course) different. It's just as if you'd compare 'abcd' with 'ab0cd'
SELECT COUNT(*)
FROM book_data
WHERE CONVERT(DATETIME,batch_dt,101) BETWEEN '11/2/2012' and '10/31/2012'
This would be more appropriate

How do I display varchar date string with mixed format to another format?

I am using SQL server 2008 R2. I know I can use CONVERT with different format code as the third parameter to do the conversion to DATETIME first and CONVERT again to VARCHAR with another format code to change the display format.
The real problem now is I have mixed raw data in a single column. So my question is how do you write a single SELECT statement to display from mixed YYYY/MM/DD, DD/MM/YYYY all to DD/MM/YYYY?
I tried to use ISDATE() but it think 31/01/2013 is not a date while 01/01/2013 is a date. Now I could only think of to see if the YYYY is on the left or on the right to determine the correct input format, but I dont know how to write it out in a single SELECT statement.
Any procedure to change the format first then do a simple SELECT is not an option. I am not allowed to change the source.
Thank you
Why not just use string manipulations? Something like:
select (case when substring(d, 5, 1) = '/' -- YYYY/MM/DD
then right(d, 2)+'/'+substring(6, 2)+'/'+left(d, 4)
else d
end)
By the way, if you are choosing formats for dates when represented as strings, I highly recommend YYYY-MM-DD (or YYYY/MM/DD) because comparison operators work on them.
If you are sure that only those 2 formats (yyyy/mm/dd and dd/mm/yyyy) exist in the data, then you could probably get away with a CASE statement along the lines of:
CASE
WHEN (SUBSTRING(dateColumn, 5, 1) = '/') THEN CONVERT(datetime, dateColumn, 111)
ELSE CONVERT(datetime, dateColumn, 103)
END

SQL query to convert Date to another format

Thanks for your help. I am not able to make out the type/format of the "Value" in a Date column.I guess its in Julian Date format.
The Column is paid_month and the values are below.
200901
200902
So,please help in writing SQL query to convert the above values(Mostly in Julian Format) in the Date Column to normal date (MM/DD/YYYY) .
Thanks
Rohit
Hi,
I am sorry for missing in giving the whole information.
1)Its a Oracle Database.
2)The column given is Paid_Month with values 200901,200902
3)I am also confused that the above value gives month & year.Day isnt given if my guess is right.
4)If its not in Julian format ,then also please help me the SQL to get at least mm/yyyy
I am using a Oracle DB and running the query
THANKS i GOT THE ANSWER.
**Now,i have to do the reverse meaning converting a date 01/09/2010 to a String which has 6 digits.
Pls help with syntax-
select to_char(01/01/2010,**
It looks like YYYYMM - depending on your database variant, try STR_TO_DATE(paid_month, 'YYYYMM'), then format that.
Note: MM/DD/YYYY is not "normal" format - only Americans use it. The rest of the world uses DD/MM/YYYY
For MySQL check
http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html#function_date-format
Example:
SELECT DATE_FORMAT(NOW(), '%d/%m/%Y')
For MySQL, you would use the STR_TO_DATE function, see http://dev.mysql.com/doc/refman/5.0/en/date-and-time-functions.html#function_str-to-date
SELECT STR_TO_DATE(paid_month,'%Y%m');
Sounds like the column contains some normal dates and some YYYYMM dates. If the goal is to update the entire column, you can attempt to isolate the YYYYMM dates and update only those. Something like:
UPDATE YourTable
SET paid_month = DATE_FORMAT(STR_TO_DATE(paid_month, '%Y%m'), '%m/%d/%Y')
WHERE LENGTH(paid_month) = 6
SELECT (paid_month % 100) + "/01/" + (paid_month/100) AS paid_day
FROM tbl;
I'm not sure about how oracle concatenates strings. Often, you see || in SQL:
SELECT foo || bar FROM ...
or functions:
SELECT cat (foo, bar) FROM ...

Formatting Dates In SqlServer To Use As Comparison

This should be easy
I have a date column on table A
SELECT * FROM TABLEA
WHERE DTE = '01/02/2010'
The problem is that this is deployed onto US servers and I have no control over the date as its an arg.
How can I tell SqlServer to treat this date as being in that format??
I gave tried this:
SELECT *
FROM TABLEA
WHERE DTE = CONVERT(VARCHAR(10), '01/01/2010' , 101) AS [DD/MM/YYYY]
Your last try was almost correct, but it should have been
SELECT * FROM TABLEA WHERE AS_OF_DATE = CONVERT(DATETIME, '01/01/2010', 101)
Use a safe format. For dates (without a time component), the safe format is YYYYMMDD, e.g. today is '20100209'.
For datetimes, the safe format is YYYY-MM-DD'T'HH:mm:SS, where 'T' is the literal T, so right now is '2010-02-09T11:10:30'.
(When I'm saying safe, I mean that SQL Server always, unambiguously, knows how to convert these strings into datetime values)
Check out this reference article: The ultimate guide to the datetime datatypes
EDIT: Specifically what Tibor says about SET DATEFORMAT & SET LANGUAGE, since you mention that you have no control over the input format.
Another option is a double conversion (check performance when used as criteria):
select strTempNo, dtmTempDateStart,
convert(varchar(10), Convert(datetime, dtmTempDateStart, 103), 126) As UTCDate
I use 103 here as the data is already in UTC format but this works as well (UTC ISO8601 is 126).
If your dates are known to be always in American format you have to use 101.
Alternatively use 112 (ISO "safe" format) and cut the first 8 characters out of the string.
Data sample: (Sorry, don't have an American date table available)
521002 2008-09-1500:00:00.000 2008-09-15
580195 2008-04-1500:00:00.000 2008-04-15
530058 2008-09-2200:00:00.000 2008-09-22
580194 2008-04-0200:00:00.000 2008-04-02
500897 2008-07-0100:00:00.000 2008-07-01
500966 2008-09-2300:00:00.000 2008-09-23