?
Solved

Subtract two dateTime fields

Posted on 2009-03-31
10
Medium Priority
?
1,060 Views
Last Modified: 2012-05-06
How do I two subtract a DateTime fields in sql
Feild1 = 2009/04/05 08:00, Field2 = 2009/05/02 09:00
The dates should not be counted in the subtraction. The value to be returned should be 01:00.
0
Comment
Question by:u2envy1
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 5
  • 4
10 Comments
 
LVL 16

Assisted Solution

by:brad2575
brad2575 earned 200 total points
ID: 24028461
DATEDIFF ( datepart , startdate , enddate )

date parts listed here:
http://msdn.microsoft.com/en-us/library/ms189794.aspx
0
 
LVL 93

Assisted Solution

by:Patrick Matthews
Patrick Matthews earned 1800 total points
ID: 24028472
Try something like this:


SELECT Field1, Field2, CONVERT(datetime, CONVERT(varchar, Field2, 108)) - CONVERT(datetime, CONVERT(varchar, Field1, 108)) AS Diff
FROM SomeTable
0
 
LVL 93

Expert Comment

by:Patrick Matthews
ID: 24028486
The "round trip" CONVERT expressions have the effect of stripping the date portions of the datetime values;
similarly, had I used the format code 101 instead of 108, it would have stripped the time portions.
0
Get proactive database performance tuning online

At Percona’s web store you can order full Percona Database Performance Audit in minutes. Find out the health of your database, and how to improve it. Pay online with a credit card. Improve your database performance now!

 

Author Comment

by:u2envy1
ID: 24028589
matthewspatrick:
The CONVERT is not stripping the date properly. Im getting 12/31/1899 & 01/01/1900
0
 

Author Comment

by:u2envy1
ID: 24028634
If I have a time Value of 08:00 AM & 07:00 PM I would like a value of 12:00 returned with no AM / PM.
Will the Convert approach do this for me ?
0
 
LVL 93

Expert Comment

by:Patrick Matthews
ID: 24028635
u2envy1,

datetime values always encode a date and a time.  To enforce formatting:

SELECT Field1, Field2, CONVERT(varchar, CONVERT(datetime, CONVERT(varchar, Field2, 108)) - CONVERT(datetime, CONVERT(varchar, Field1, 108)), 108) AS Diff
FROM SomeTable

Regards,

Patrick
0
 

Author Comment

by:u2envy1
ID: 24028713
Thx Matthew.....
How do I convert the As Diff to show hh:mm only. No seconds ?
0
 
LVL 93

Accepted Solution

by:
Patrick Matthews earned 1800 total points
ID: 24028741
SELECT Field1, Field2, LEFT(CONVERT(varchar, CONVERT(datetime, CONVERT(varchar, Field2, 108)) - CONVERT(datetime, CONVERT(varchar, Field1, 108)), 108), 5) AS Diff
FROM SomeTable
0
 

Author Closing Comment

by:u2envy1
ID: 31564795
Thx, its working perfectly......
0
 

Author Comment

by:u2envy1
ID: 24036338
One more thing. Is it possible to Sum(Diff) ?
0

Featured Post

What is SQL Server and how does it work?

The purpose of this paper is to provide you background on SQL Server. It’s your self-study guide for learning fundamentals. It includes both the history of SQL and its technical basics. Concepts and definitions will form the solid foundation of your future DBA expertise.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

International Data Corporation (IDC) prognosticates that before the current the year gets over disbursing on IT framework products to be sent in cloud environs will be $37.1B.
I have a large data set and a SSIS package. How can I load this file in multi threading?
Via a live example, show how to extract insert data into a SQL Server database table using the Import/Export option and Bulk Insert.
Viewers will learn how to use the UPDATE and DELETE statements to change or remove existing data from their tables. Make a table: Update a specific column given a specific row using the UPDATE statement: Remove a set of values using the DELETE s…
Suggested Courses

752 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