Date equality in select statement

Question

Date equality in select statement giving 0 result even table contains record matching to it.please suggest what wrong in this query
1- select *from  EOE_POC.PRODUCT_TEST_REPORT where CREATE_DATE = '03-SEP-13'
2 - select *from  EOE_POC.PRODUCT_TEST_REPORT where CREATE_DATE >= '03-SEP-13'
above query (2nd one) is giving 2 records.But I am intend to check for equality not greater ..plz enlighten

Answer 1

Deekay wrote:
Thanks Bhushan.
select *from  EOE_POC.PRODUCT_TEST_REPORT where CREATE_DATE = sysdate
can u plz throw some more light how to check by sysdate?
Assuming CREATE_DATE is -- as it should be -- defined as a DATE (not a varchar) you need to be aware of the fact that DATEs always carry "time" as well.   So sysdate is not just "today", it is "this very second".    That's why you need to consider the use of TRUNC when you want to compare dates without consideration for the time.
The other thing you need to be aware of is that the literal '03-SEP-13' is not a DATE, but a character string that humans would tend to recognize as representing a date.  But to a computer it is still just a character string, fundamentally no different from "here's yer sign!".  Therefore, in your usage of comparing the character string '03-SEP-13' to the DATE in CREATE_DATE, oracle has to to an implicit conversion.  And to do that implicit conversion it has to know what part of the character string represents the day, the month, the year, and possibly the hour, minute, and second.  To do this, it relies on the current setting of NLS_DATE_FORMAT, which may or may not be what you expect.    Please see: http://edstevensdba.wordpress.com/2011/04/07/nls_date_format/ - But I want to store my date as ...  for a more complete explanation.
And finally, why are you using 2-digit years?  Are you actually working in IT and never heard of "the Y2K problem"?  Fifteen years ago I and thousands of my colleagues began a two-year grind of busting our butts to make sure systems continued to function correctly when the current date became 01-Jan-2000.  Please don't repeat the same mistakes that caused that problem.