Solved

format date from yyyy/mm/dd to mm/dd/yyyy when this field is varchar type

Posted on 2004-10-04
19
484 Views
Last Modified: 2009-07-29
Hi,

We need to format date from yyyy/mm/dd to mm/dd/yyyy when this field type is char. Could anyone help us on this?

THanks.
0
Comment
Question by:mei_liu
  • 8
  • 5
  • 4
  • +1
19 Comments
 
LVL 1

Accepted Solution

by:
xabimond earned 500 total points
ID: 12220722
If the data format is yyyy-mm-dd then you can convert to a datetime specifying the style like this:

select convert(datetime, '2004-10-04', 120)

if you want to convert this back to a char, but American date format then use this:

select convert(varchar, convert(datetime, '2004-10-04', 120), 101)

If you start date actually has the "/" rather than "-" the you'll need to use substring to reformat the date.  To convert to datetime do this:

select convert(datetime, substring('2004-10-04', 6, 2) + '/' + substring('2004-10-04', 9, 2) + '/' + substring('2004-10-04', 1, 4), 101)

or to char, but American format.

select substring('2004-10-04', 6, 2) + '/' + substring('2004-10-04', 9, 2) + '/' + substring('2004-10-04', 1, 4)

Remember SQL server doesn't hold dates in a particular style they are held as number where the integer part is the number of days past 1900-01-01 and the decimal represent miliseconds throught the day.   So most of the above is superfluous if you're just converting the char format to datetime.  You only have to worry about the format when you want to display the date.

Hope some of this helps!
0
 
LVL 34

Expert Comment

by:arbert
ID: 12220812
What?  format 101 will give you slashes:

select convert(varchar(10),getdate(),101)

returns:  10/04/2004
0
 
LVL 34

Expert Comment

by:arbert
ID: 12220824
Convert(varchar(10),getdate(),110) will return dashes:

10-04-2004
0
 

Author Comment

by:mei_liu
ID: 12220912
Thanks for your response. Here is what we have received:

"The conversion of a char data type to a datetime data type resulted in an out-of-range datetime value." How could we ignore the invalid date entered in the system, yet continue converting varchar type to datetime type?

Thanks.
0
 
LVL 6

Expert Comment

by:mcp111
ID: 12220918
select convert(varchar(20),convert(datetime, '2004-10-04', 101),101)
0
 
LVL 34

Expert Comment

by:arbert
ID: 12220965
Select case isdate(yourdatecolumn)
   when 1 then convert(varchar(10),yourdate,101)
   else NULL end YourNewDate
0
 
LVL 34

Expert Comment

by:arbert
ID: 12220988
mcp111, select convert(varchar(20),convert(datetime, '2004-99-04', 101),101) returns a conversion error....
0
 
LVL 1

Expert Comment

by:xabimond
ID: 12220997
Format 101 will give you dashes but yyyy/mm/dd is not a recognised SQL Server date format hence the substrings.
0
 

Author Comment

by:mei_liu
ID: 12221029
xabimond's select substring('2004-10-04', 6, 2) + '/' + substring('2004-10-04', 9, 2) + '/' + substring('2004-10-04', 1, 4)
 worked. It also ignored the invalid date users entered.

Thanks all!
0
Highfive + Dolby Voice = No More Audio Complaints!

Poor audio quality is one of the top reasons people don’t use video conferencing. Get the crispest, clearest audio powered by Dolby Voice in every meeting. Highfive and Dolby Voice deliver the best video conferencing and audio experience for every meeting and every room.

 
LVL 6

Expert Comment

by:mcp111
ID: 12221052
arbert

please copy and paste properly before testing.
it is '2004-10-04' not '2004-99-04' as you have indicated in your post.
I have tested my code and it works fine!
0
 
LVL 34

Expert Comment

by:arbert
ID: 12221072
"recognised SQL Server date format hence "

Sure it is....

mcp111, I know, I was pasting to show you what happens with invalid dates....Mei_liu posted ""The conversion of a char data type to a datetime data type resulted in an out-of-range datetime value."    So I tested your post with invalid dates and it returned the same thing....
0
 
LVL 6

Expert Comment

by:mcp111
ID: 12221118
I think my code is much more compact than xabimond's.

Also this is incorrect
"If you start date actually has the "/" rather than "-" the you'll need to use substring to reformat the date"

Check this code out. It works fine!

select convert(varchar(20),convert(datetime, '2004/10/04', 101),101)

It doesn't make any difference whether it is "/" or "-" in the input.
0
 
LVL 34

Expert Comment

by:arbert
ID: 12221210
but it doesn't account for invalid dates...
0
 
LVL 6

Expert Comment

by:mcp111
ID: 12221231
arbert.

even xabimond's code will not work with invalid dates.

I don't know how mei liu can say this
---------------------------------------------------------------------------
xabimond's select substring('2004-10-04', 6, 2) + '/' + substring('2004-10-04', 9, 2) + '/' + substring('2004-10-04', 1, 4)
 worked. It also ignored the invalid date users entered.

Try putting 2004-99-04, an invalid date in this.

Date validation should be done at the front end and only valid data passed to sql.
0
 
LVL 34

Expert Comment

by:arbert
ID: 12221298
Not sure--that's why I posted the code above with ISDate--it does work....
0
 

Author Comment

by:mei_liu
ID: 12221564
I know for fact that our data were entered wrong for some records. When I tested xabimond's code, it worked.

0
 
LVL 6

Expert Comment

by:mcp111
ID: 12221593
mei liu:

don't you have validation in data entry to prevent wrong dates being entered? That should be your first step.

If you put 2004-99-04 in xabimond's code,it returns 99/10/2004
which is certainly not a valid date!
0
 

Author Comment

by:mei_liu
ID: 12221864
Yes, I agree with you that 99/04/2004 is not a valid date; however, it is a "valid" in a sense that it matches what the end user entered.

When I tested your date "2004-99-01", it returned to me as "99/04/2004".
0
 
LVL 34

Expert Comment

by:arbert
ID: 12222102
"Yes, I agree with you that 99/04/2004 is not a valid date; however, it is a "valid" in a sense that it matches what the end user entered."

Doesn't really sound valid then does it....GIGO
0

Featured Post

Maximize Your Threat Intelligence Reporting

Reporting is one of the most important and least talked about aspects of a world-class threat intelligence program. Here’s how to do it right.

Join & Write a Comment

Suggested Solutions

In this article—a derivative of my DaytaBase.org blog post (http://daytabase.org/2011/06/18/what-week-is-it/)—I will explore a few different perspectives on which week today's date falls within using Microsoft SQL Server. First, to frame this stu…
Introduction SQL Server Integration Services can read XML files, that’s known by every BI developer.  (If you didn’t, don’t worry, I’m aiming this article at newcomers as well.) But how far can you go?  When does the XML Source component become …
Via a live example combined with referencing Books Online, show some of the information that can be extracted from the Catalog Views in SQL Server.
Viewers will learn how the fundamental information of how to create a table.

708 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

14 Experts available now in Live!

Get 1:1 Help Now