Regarding dates query

Question

i have table which contains dates in format like yyyy-mm-dd but some of dates are only
yyyy-mm and yyyy so i need a query for finding dates which are not belongs to this format.query should give result like that other than my format like yyyy-mm-dd

Answer 1

Hi,
As the others have said, all Oracle DATEs are stroed in the same format, which always includes the month and day. (It always includes hours, minutes and seconds, too.)
It sounds like you have a string (such as VARCHAR2) which is supposed to represent a date. That's a very bad idea, as the others have said, and you really should change the table to use a DATE instead.
Assuming the fomatting of those strings is consistent, then you can tell which of the strings include day, whichinclude just year and month, and which include year only by looking at the LENGTH.
If you want to convert them all to DATEs, here's one way:
CASE  LENGTH (column_x)
    WHEN  10                         -- Includes year, month and day
    THEN  TO_DATE (column_x, 'YYYY-MM-DD')
    WHEN   7                         -- Includes year and month, but not day
    THEN  TO_DATE (column_x, 'YYYY-MM')          -- Day will be '01'
    WHEN   4                         -- Just year
    THEN  TRUNC ( TO_DATE (column_x, 'YYYY')     
          , 'YYYY
          )                    -- Month-day will be '01-01'
ENDThe expression above shows how you can test the LENGTH of the string.
You could get the same results this way, too:
TO_DATE ( SUBSTR ( column_x || '-01-01'
           , 1
           , 10
     , 'YYYY-MM-DD'
     )I hope this an\swers your question.
If not, post a little sample data (CREATE TABLE and INSERT statemnents) and the results you want from that data.