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sqloracle-databaselagteradatalead

Teradata equivalent for lead and lag function of oracle


I have been working ot see the equivalent function for Oracle lead and lag function.

The oracle lead would look like

LEAD(col1.date,1,ADD_MONTHS(col1.DATE,12)) 
OVER(Partition By tab.a,tab.b,tab.c Order By tab.a)-1 END_DATE

LAG(col1.DATE + 7,1,col1.DATE-1) 
OVER(partition by tab.a,tab.b Order By tab.b) LAG_DATE

Any better idea


Solution

  • I believe you can take the following SQL as a basis and modify it to meet your needs:

    SELECT CALENDAR_DATE
         , MAX(CALENDAR_DATE)
           OVER(PARTITION BY 1 ORDER BY CALENDAR_DATE
                ROWS BETWEEN 1 PRECEDING AND 1 PRECEDING) AS Lag_ --Yesterday
         , MIN(CALENDAR_DATE)
                OVER(PARTITION BY 1 ORDER BY CALENDAR_DATE
                ROWS BETWEEN 1 FOLLOWING AND 1 FOLLOWING) AS Lead_ --Tomorrow
    FROM SysCalendar.CALENDAR
    WHERE year_of_calendar = 2011
      AND month_of_year = 11
    

    NULL is returned when there is no record before or after and can be addressed with a COALESCE as necessary.

    EDIT In Teradata 16.00 LAG/LEAD functions were introduced.