?
Solved

find difference between dates from a column in oracle

Posted on 2016-08-08
9
Medium Priority
?
101 Views
Last Modified: 2016-08-09
I have this data
Emp#           eff_dt                type       seq_nbr     Expected column
1234            7/18/2011      HIRE      1                null
1234           11/23/2012      TERM      2                 16
1234           9/8/2014              HIRE      3                 21
1234            8/23/2015      TERM      4                 11

i need to add another column which would give me difference between eff_dt in Months.
0
Comment
Question by:need_solution
  • 3
  • 3
  • 2
  • +1
9 Comments
 
LVL 5

Expert Comment

by:Abhimanyu Suri
ID: 41747962
Please try this

  SELECT emp#,
         eff_date,
         LAG (eff_dt) OVER (PARTITION BY emp# ORDER BY eff_dt),
         MONTHS_BETWEEN (
            eff_date - LAG (eff_dt) OVER (PARTITION BY emp# ORDER BY eff_dt))
    FROM TABLE_TEST
ORDER BY emp#

example, for below mentioned data :

42927      8/4/2016 2:00:10.724 AM
42934      8/4/2016 9:00:33.372 AM
43030      8/8/2016 9:00:44.225 AM
42852      7/31/2016 11:01:00.293 PM

Query Result

42852      7/31/2016 11:01:00.293 PM            
42927      8/4/2016 2:00:10.724 AM      7/31/2016 11:01:00.293 PM      0.1
42934      8/4/2016 9:00:33.372 AM      8/4/2016 2:00:10.724 AM      0
43030      8/8/2016 9:00:44.225 AM      8/4/2016 9:00:33.372 AM      0.13

NOTE : Don't take it as an as is solution, you may need to handle NULL and tweak it as per other columns in mentioned example.
0
 
LVL 32

Expert Comment

by:awking00
ID: 41748761
A couple of modifications to Abhimanyu Suri's solution - MONTHS_BETWEEN requires two parameters and FLOOR rounds down the months to a whole number -
SELECT emp#, eff_dt, type, seq_nbr,
FLOOR(MONTHS_BETWEEN (eff_dt, LAG (eff_dt) OVER (PARTITION BY emp# ORDER BY eff_dt))) expected_column
FROM your_table
ORDER BY emp#;
0
 
LVL 5

Expert Comment

by:Abhimanyu Suri
ID: 41748768
Thanks for correctio "awking" it appears '-' got copied over for  ','
0
Concerto's Cloud Advisory Services

Want to avoid the missteps to gaining all the benefits of the cloud? Learn more about the different assessment options from our Cloud Advisory team.

 

Author Comment

by:need_solution
ID: 41749133
Thanks much for the solution but the ORacle version we have in our organization does not support LAG() function
0
 
LVL 5

Expert Comment

by:Abhimanyu Suri
ID: 41749219
I have created a script based on dba_hist_snapshot, you will have to introduce partition by clause in dense rank for employee_id and also in where clause a join on employee_id

Hopefully dense_rank will work for you :)

SELECT b.snap_id,
       b.begin_interval_time,
        a.begin_interval_time,
       MONTHS_BETWEEN (b.begin_interval_time, a.begin_interval_time)
  FROM (SELECT snap_id,
               begin_interval_time,
               DENSE_RANK () OVER (ORDER BY begin_interval_time) rnk
          FROM dba_hist_snapshot
         WHERE snap_id IN (43012,
                           43020,
                           43028,
                           43032,
                           43037)) b,
       (SELECT snap_id,
               begin_interval_time,
               DENSE_RANK () OVER (ORDER BY begin_interval_time) rnk
          FROM dba_hist_snapshot
         WHERE snap_id IN (43012,
                           43020,
                           43028,
                           43032,
                           43037)) a
 WHERE  b.rnk - 1 = a.rnk (+)
 order by 1

Sample data by lag Query
snap_id     begin_interval_time         LAG (begin_interval_time)     DIFF                      
43012       8/7/2016 3:00:46.993 PM            
43020       8/7/2016 11:00:12.383 PM    8/7/2016 3:00:46.993 PM         0    
43028       8/8/2016 7:00:37.560 AM     8/7/2016 11:00:12.383 PM        0.01
43032       8/8/2016 11:00:50.881 AM    8/8/2016 7:00:37.560 AM         0    
43037       8/8/2016 4:00:06.712 PM     8/8/2016 11:00:50.881 AM        0  

Sample data by above mentioned SQL

snap_id  begin_interval_time            LAG (begin_interval_time)     DIFF                              
43012    8/7/2016 3:00:46.993 PM        
43020    8/7/2016 11:00:12.383 PM       07-AUG-16 15.00.46.993          0
43028    8/8/2016 7:00:37.560 AM        07-AUG-16 23.00.12.383          0.010
43032    8/8/2016 11:00:50.881 AM       08-AUG-16 07.00.37.560          0
43037    8/8/2016 4:00:06.712 PM        08-AUG-16 11.00.50.881          0
0
 
LVL 41

Accepted Solution

by:
Sharath earned 2000 total points
ID: 41749356
try this.
SELECT t1.*,CAST(MONTHS_BETWEEN(t1.eff_dt, t2.eff_dt) AS INTEGER) Expected_Column
  FROM your_table t1
  LEFT JOIN your_table t2 ON t1.seq_nbr = t2.seq_nbr + 1;

Open in new window

0
 
LVL 32

Expert Comment

by:awking00
ID: 41749359
What is your version of Oracle? Whatever version, you can probably get by with row_number() and a self-join-
select h1.emp#, h1.eff_dt, h1.type, h1.seq_nbr,
floor(months_between(h1.eff_dt, h2.eff_dt))
from
(select emp#, eff_dt, type, seq_nbr,
 row_number() over (partition by emp# order by eff_dt) rn
 from yourtable) h1
left join
(select emp#, eff_dt,
 row_number() over (partition by emp# order by eff_dt) rn
 from yourtable) h2
on h1.emp# = h2.emp#
and h1.rn - 1 = h2.rn
order by emp#, eff_dt;
0
 

Author Closing Comment

by:need_solution
ID: 41749374
Thank you Sharath, it worked!
0
 
LVL 32

Expert Comment

by:awking00
ID: 41749392
That works fine for one emp# but what happens to the seq_nbr when a new emp# is encountered? If it re-increments (similar to row_number) for each emp#, then it should also work.
0

Featured Post

NEW Veeam Backup for Microsoft Office 365 1.5

With Office 365, it’s your data and your responsibility to protect it. NEW Veeam Backup for Microsoft Office 365 eliminates the risk of losing access to your Office 365 data.

Question has a verified solution.

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

This article started out as an Experts-Exchange question, which then grew into a quick tip to go along with an IOUG presentation for the Collaborate confernce and then later grew again into a full blown article with expanded functionality and legacy…
Truncate is a DDL Command where as Delete is a DML Command. Both will delete data from table, but what is the difference between these below statements truncate table <table_name> ?? delete from <table_name> ?? The first command cannot be …
This video shows how to Export data from an Oracle database using the Original Export Utility.  The corresponding Import utility, which works the same way is referenced, but not demonstrated.
Via a live example, show how to restore a database from backup after a simulated disk failure using RMAN.
Suggested Courses

757 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