CODEWITHSUNDEEP
sqlsql-servert-sqldatediff
Tyrone2011
Tyrone2011

Reputation: 269

SQL Datediff - find datediff between rows

I would like to query a database using sql to show the difference in time between id 1,2,3 and so on. basically it will compare the row below it for all records. any help would be appreciated. 

IDCODE  DATE TIME        DIFFERENCE (MINS)
1      02/03/2011 08:00        0
2      02/03/2011 08:10        10
3      02/03/2011 08:23        13
4       02/03/2011 08:25        2
5       02/03/2011 09:25        60
6       02/03/2011 10:20        55
7       02/03/2011 10:34        14

Thanks!

Upvotes: 26

Views: 39307

Answers (3)

Timmy B
Timmy B

Reputation: 11

As @a_horse_with_no_name mentioned using the lag()

I wanted in millisecond what the diff was.

Select idcode,
       datetime,
       Difference = datediff(millisecond, lag(convert(datetime2,datetime)) over (order by convert(datetime2,datetime)),convert(datetime2,datetime))
From your_table

in my case I needed to convert a string to a datetime2

Upvotes: 1

AdaTheDev
AdaTheDev

Reputation: 147354

If using SQL Server, one way is to do:

DECLARE @Data TABLE (IDCode INTEGER PRIMARY KEY, DateVal DATETIME)
INSERT @Data VALUES (1, '2011-03-02 08:00')
INSERT @Data VALUES (2, '2011-03-02 08:10')
INSERT @Data VALUES (3, '2011-03-02 08:23')
INSERT @Data VALUES (4, '2011-03-02 08:25')
INSERT @Data VALUES (5, '2011-03-02 09:25')
INSERT @Data VALUES (6, '2011-03-02 10:20')
INSERT @Data VALUES (7, '2011-03-02 10:34')

SELECT t1.IDCode, t1.DateVal, ISNULL(DATEDIFF(mi, x.DateVal, t1.DateVal), 0) AS Mins
FROM @Data t1
    OUTER APPLY (
        SELECT TOP 1 DateVal FROM @Data t2 
        WHERE t2.IDCode < t1.IDCode ORDER BY t2.IDCode DESC) x

Another way is using a CTE and ROW_NUMBER(), like this:

;WITH CTE AS (SELECT ROW_NUMBER() OVER (ORDER BY IDCode) AS RowNo, IDCode, DateVal FROM @Data)

SELECT t1.IDCode, t1.DateVal, ISNULL(DATEDIFF(mi, t2.DateVal, t1.DateVal), 0) AS Mins
FROM CTE t1
    LEFT JOIN CTE t2 ON t1.RowNo = t2.RowNo + 1
ORDER BY t1.IDCode

Upvotes: 34

user330315
user330315

Reputation:

Standard ANSI SQL solution. Should work in PostgreSQL, Oracle, DB2 and Teradata:

SELECT idcode, 
       date_time, 
       date_time - lag(date_time) over (order by date_time) as difference
FROM your_table

Upvotes: 21

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