SQL Datediff - find datediff between rows

问题

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!

回答1:

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

回答2:

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

来源：https://stackoverflow.com/questions/5728602/sql-datediff-find-datediff-between-rows

标签

sql

sql-server

tsql

datediff