Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>Solution:</p> <pre><code>DECLARE @Event TABLE( EventID INT IDENTITY(1,1) NOT NULL PRIMARY KEY, CardNo VARCHAR(10) NOT NULL, [Login] DATETIME NOT NULL -- To prevent duplicate events -- This constraint will create an index used to optimize the RowNum and the last queries UNIQUE(CardNo,[Login]) ); INSERT INTO @Event(CardNo,[Login]) SELECT 'E44920', '2013-07-15T09:18:00' UNION ALL SELECT 'E44920', '2013-07-15T09:46:00' UNION ALL SELECT 'E44920', '2013-07-15T17:09:00' UNION ALL SELECT 'E44920', '2013-07-15T16:57:00' UNION ALL SELECT 'E44920', '2013-07-15T17:34:00' UNION ALL SELECT 'E44920', '2013-07-15T17:53:00'; DECLARE @EventWithRowNum TABLE( RowNum INT NOT NULL, CardNo VARCHAR(10) NOT NULL, PRIMARY KEY (CardNo,RowNum), [Login] DATETIME NOT NULL UNIQUE(CardNo,[Login]) ); INSERT INTO @EventWithRowNum (CardNo,[Login],RowNum) SELECT e.CardNo, e.[Login], ROW_NUMBER() OVER(PARTITION BY e.CardNo ORDER BY e.[Login]) AS RowNum FROM @Event e; -- Final query SELECT crt.RowNum, crt.CardNo, crt.[Login] AS CurrentLogin, nxt.RowNum, nxt.[Login] AS NextLogin, DATEDIFF(SECOND, crt.Login, nxt.Login) AS Diff_Seconds FROM @EventWithRowNum crt -- crt = odd rows LEFT JOIN @EventWithRowNum nxt ON crt.CardNo=nxt.CardNo AND crt.RowNum=nxt.RowNum-1 -- nxt = even rows WHERE crt.RowNum % 2 = 1 -- odd rows; you could add a computed column Modulo2 AS (RowNum % 2) PERSISTED and then you could define a index (key: Modulo2, CardNo, Login) ORDER BY crt.CardNo, crt.[Login]; </code></pre> <p>Results:</p> <pre><code>RowNum CardNo Current_Login RowNum Next_Login Diff_Seconds ----------- ---------- ----------------------- ----------- ----------------------- ------------ 1 E44920 2013-07-15 09:18:00.000 2 2013-07-15 09:46:00.000 1680 3 E44920 2013-07-15 16:57:00.000 4 2013-07-15 17:09:00.000 720 5 E44920 2013-07-15 17:34:00.000 6 2013-07-15 17:53:00.000 1140 </code></pre>
    singulars
    1. This table or related slice is empty.
    1. POFind difference between rows of same column (difference between time data)
      singulars
      1. PTQuestion
    1. PTAnswer
    1. This table or related slice is empty.
    1. USBogdan Sahlean
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COHi @bogdan-sahlean,thanks for your solution its working fine,i jst want to modify this query as if this diffrence between 1st and 2nd is less than 5 mins then the difference should be calculated between 1st and 3rd else 1st and 4th ..so hw can i do this..plz giv solution
      singulars
      1. PO
      1. USshweta
    2. COplz provide solution
      singulars
      1. PO
      1. USshweta
    3. CO@shweta: your question is *find difference between 1st and 2nd login time.. then 3rd and 4th login time*. Now you want a solution for *another problem/question*. You should create another question. My answer is a solution for your [intial] question.
      singulars
      1. PO
      1. USBogdan Sahlean
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload