Timestamp column loading error

Question

hi ,
I am 1 table as below.               
CREATE TABLE DBMG_SAL_HEAD (
CM_DATE DATE,
CM_TIME VARCHAR2(8),
data in table is..
CM_DATE     CM_TIME
10/20/2010 13:09:06
now I need to insert above data in below table with 1 second less time ex-10/20/2010 13:09:05
CREATE TABLE PC (
COL1 TIMESTAMP(9)
how I can do it??
I tried below query but when I entered in table its not showing correct format..I m using oracle 11g.
select TO_DATE( TO_CHAR(TO_DATE( CM_DATE||' '||CM_TIME,'dd-mm-yyyy hh24:mi:ss'),'dd-mm-yyyy hh24:mi:')||
          TO_CHAR(TO_CHAR(TO_DATE( CM_TIME,'hh24:mi:ss'),'ss')-1) ,'dd-mm-yyyy hh24:mi:ss') cr_date
FROM DBMG_SAL_HEAD ;
o/p is correct as i need..
10/20/0010 1:09:05 PM
now i m inserting ..
insert into pc
select TO_DATE( TO_CHAR(TO_DATE( CM_DATE||' '||CM_TIME,'dd-mm-yyyy hh24:mi:ss'),'dd-mm-yyyy hh24:mi:')||
          TO_CHAR(TO_CHAR(TO_DATE( CM_TIME,'hh24:mi:ss'),'ss')-1) ,'dd-mm-yyyy hh24:mi:ss') cr_date
FROM DBMG_SAL_HEAD ;
commit;
select * from pc;
o/p is
20-OCT-10 0 why data is coimng like this ??i need it in 10/20/0010 1:09:05 PM format...
plz fix it..........!
rgds,
pc

Answer 1

PC wrote:
hi ,
I am 1 table as below.               
CREATE TABLE DBMG_SAL_HEAD (
CM_DATE DATE,
CM_TIME VARCHAR2(8),
Bad design from the get-go. DATE data holds both date and time. No justification for having a separate column for time only.
data in table is..
CM_DATE     CM_TIME
10/20/2010 13:09:06
now I need to insert above data in below table with 1 second less time ex-10/20/2010 13:09:05
CREATE TABLE PC (
COL1 TIMESTAMP(9)
how I can do it??
I tried below query but when I entered in table its not showing correct format..I m using oracle 11g.
select TO_DATE( TO_CHAR(TO_DATE( CM_DATE||' '||CM_TIME,'dd-mm-yyyy hh24:mi:ss'),'dd-mm-yyyy hh24:mi:')||
          TO_CHAR(TO_CHAR(TO_DATE( CM_TIME,'hh24:mi:ss'),'ss')-1) ,'dd-mm-yyyy hh24:mi:ss') cr_date
FROM DBMG_SAL_HEAD ;
o/p is correct as i need..
10/20/0010 1:09:05 PM
now i m inserting ..
insert into pc
select TO_DATE( TO_CHAR(TO_DATE( CM_DATE||' '||CM_TIME,'dd-mm-yyyy hh24:mi:ss'),'dd-mm-yyyy hh24:mi:')||
          TO_CHAR(TO_CHAR(TO_DATE( CM_TIME,'hh24:mi:ss'),'ss')-1) ,'dd-mm-yyyy hh24:mi:ss') cr_date
FROM DBMG_SAL_HEAD ;
commit;
select * from pc;
o/p is
20-OCT-10 0 why data is coimng like this ??i need it in 10/20/0010 1:09:05 PM format...
plz fix it..........!You fix it.
You need to understand that DATE and TIMESTAMP are stored in oracle's internal format. They are presented in a query with the formatting specified by the controlling setting of your NLS parameters. That's what to_char and to_date are all about.
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If the column is defined as a DATE, then the data is NOT+ stored in the format you stated. Oracle always stores dates in its own internal format.
What you are referring to is the character string representation of the data. That presentation is controlled by the controlling setting of NLS_DATE_FORMAT. The reason I say the "controlling" setting is because NLS_DATE_FORMAT can be set in any of several different locations, each with its own scope of influence. That being the case you should never depending on a setting outside of your own control. That means you will always do one of the following:
1) ALTER SESSION SET NLS_DATE_FORMAT='whatever format mask you want';
or
2) Proper use of TO_CHAR and TO_DATE at the individual sql statement
I prefer the second, so there is never any ambiguity or question when looking at an individual SQL statement.
Just to drive home the point:
SQL> create table mytable (mydate date);
Table created.
SQL> insert into mytable values (to_date('09-15-2010','mm-dd-yyyy'));
1 row created.
SQL> insert into mytable values (to_date('20091225','yyyymmdd'));
1 row created.
SQL> insert into mytable values (to_date('1970-06-25 15:45:37','yyyy-mm-dd hh24:mi:ss'));
1 row created.
SQL> commit;
Commit complete.
SQL> select * from mytable;
MYDATE
15-SEP-10
25-DEC-09
25-JUN-70
3 rows selected.
SQL> select to_char(mydate,'yyyymmdd') from mytable;
TO_CHAR(
20100915
20091225
19700625
3 rows selected.
SQL> select to_char(mydate,'mmMON-dd-yy hh:mi') from mytable;
TO_CHAR(MYDATE,'MMM
09  SEP-15-10 12:00
12  DEC-25-09 12:00
06  JUN-25-70 03:45
3 rows selected.
SQL> select to_char(mydate,'MON-dd-yyyy hh24:mi') from mytable;
TO_CHAR(MYDATE,'M
SEP-15-2010 00:00
DEC-25-2009 00:00
JUN-25-1970 15:45
3 rows selected.
SQL> Through any of the above, was the format of the stored data ever changed?
>
rgds,
pc