selecting data fom a view throws error - sql

Question

I get input as 2011/11/13 00:00:00. So I made the query as:
select * from xxcust_pfoa434p_vw
where week_ending_date = to_date(substr(:value,1,10),'YYYY/MM/DD')
The same statement gives proper result when queried against other tables. But throws error when I query this against the view xxcust_pfoa434p_vw
I have a view xxcust_pfoa434p_vw which has a column week_ending_date of date data type.
The value in that column is like 3/2/2014,12/25/2011 i.e. MM/DD/YYYY
Even
select * from xxcust_pfoa434p_vw where week_ending_date='3/2/2014'
also gives
ORA-01843: not a valid month. What is the cause for this error.

Answer 1

You say
"The same statement gives proper result when queried against other
tables. But throws error when I query this against the view
xxcust_pfoa434p_vw"
So clearly the problem is with the view. You also say
"[the view] has a column week_ending_date of date data type. The value
in that column is like 3/2/2014,12/25/2011 i.e. MM/DD/YYYY "
Those values would only display like that if the default date mask for you system were MM/DD/YYYY. This is easy enough to check with the query
select * from V$NLS_PARAMETERS
where parameter = 'NLS_DATE_FORMAT';
Personally, my money is on that column not being a date column. ORA-01841 always indicates oracle attempting to cast a string into a date and finding a value which doesn't fit the explicit or default format mask. Plus the so-called date '3/2/2014' lacks leading zeroes and that's suspicious too.
I think whoever wrote that view decided to fix the format of week_ending_date and so deployed TO_CHAR to present a string not a date datatype. A DESC in SQL*Plus or looking at the view TEXT in ALL_VIEWS will reveal the answer.

Answer 2

select * from xxcust_pfoa434p_vw
where week_ending_date=to_date('03/02/2014','MM/DD/YYYY');

Answer 3

Even if you see formatted date in this format - it is only a visual representation, when oracle process your query it automatically convers string given by you into its own interal representation.
It is always better to use proper SQL one YYYY-MM-DD:
for 2nd march: select * from xxcust_pfoa434p_vw where week_ending_date = to_date('2014-03-02', 'YYYY-MM-DD')
for 3rd february: select * from xxcust_pfoa434p_vw where week_ending_date = to_date('2014-02-03', 'YYYY-MM-DD')
this conforms to SQL standard and do not produce confusion between DD/MM/YYYY and MM/DD/YYYY
Just quote from standard:
There is an ordering of the significance of <datetime field>s. This
is, from most significant to least significant: YEAR, MONTH, DAY,
HOUR, MINUTE, and SECOND.
UPDATE: it is very good idea always use to_date function to specify exact format and avoid dependancy on any kind of localization settings