Identify date format in PLSQL - sql

Question

I'm trying to write a plsql stored procedure which identifies any date format and converts it into single datetime format 'mm/dd/yyyy hh:mi:ss'. How do I do it. I tried using case statment but there are so many date combinations that its not possible to write case statment for all of them.
For ex: 27-Oct-1967, October 27 1967 11:15:45, 1967-OCT-27, etc.
How do I convert all these to single format.
Thank you.

Answer 1

Simply to_char() will do,
select to_char(yourDateField,'mm/dd/yyyy hh:mi:ss') from dual;

Answer 2

Maybe this can help you:
CREATE TABLE temp_date
AS
SELECT '1967-OCT-27' some_date
FROM dual
UNION
SELECT '27-Oct-1967' FROM dual
UNION
SELECT 'October 27 1967 11:15:45' FROM dual
/
Declare
CURSOR i_cur IS
Select some_date
From temp_date;
--
v_date1 Varchar2(30);
v_date2 Varchar2(30);
v_date3 Varchar2(30);
v_char Varchar2(30);
v_cnt Number:= 0;
Begin
For i_rec IN i_cur
Loop
v_cnt:= v_cnt + 1;
Begin
v_date1:= to_char(to_date(i_rec.some_date), 'MM/DD/YYYY hh24:mi:ss');
dbms_output.put_line(v_cnt||'.'||chr(9)||v_date1);
EXCEPTION
When Others Then
Begin
v_date2:= to_char(to_date(i_rec.some_date, 'MM/DD/YYYY hh24:mi:ss'), 'MM/DD/YYYY hh24:mi:ss');
dbms_output.put_line(v_cnt||'.'||chr(9)||v_date2);
EXCEPTION
When Others Then
Begin
v_date3:= to_char(to_date(i_rec.some_date, 'YYYY-MON-DD'), 'MM/DD/YYYY hh24:mi:ss');
dbms_output.put_line(v_cnt||'.'||chr(9)||v_date3);
EXCEPTION
When Others Then
-- Insert into Exceptions table (or any temp table) then convert... --
v_char:= i_rec.some_date;
dbms_output.put_line(v_cnt||'. '||chr(9)||i_rec.some_date||' : '||v_char);
End;
End;
End;
End Loop;
End;
/
1. 10/27/1967 00:00:00
2. 10/27/1967 00:00:00
3. 10/27/1967 11:15:45

Answer 3

The most desired way of would be to formatting date into the format that you need. Then do whatever calculations that you require on it.
Otherwise you will have to write ridiculously large number of select cases to define the format. Not to say that it doesn't make sense since dates can come in many different formats....as Mat mentioned. And further Date is a component that can be influenced by your system.
You may try the following:
Convert date input into the desired format using To_Date() given you may not even know if this input comes as a String or a real date. So you may need some validations to make sure it's a proper date.
SELECT TO_DATE(mydate,'mm/dd/yyyy hh:mi:ss') FROM Dual;