Change "Date" From a Column in Table A, to New Column in Table B:

Question

I'm trying to pull a Date from TABLE_A, and change the year to a current date, and popluate this into a new table. I also want to pull the PK of TABLE_A over, so that I can create a link back to the master record.
In my example I'm useing SYSDATE for my current date. Once I get the script working, I want to pull the Calander_Date from my "Current Calendar" in APEX.
1. INSERT INTO TABLE_B (NAME_ID,Date,New_Date VALUES (
2. NAME_ID , (This is a Column FROM TABLE_A),
3. DATE, (This is also a Colum From TABLE_A)
4. TO_CHAR(DATE,'DD')||'-'||
5. TO_CHAR(DATE,'MON')||'-'||
6. TO_CHAR(SYSDATE,'YY') )
7. FROM TABLE_A
8 WHERE TO_CHAR(DATE,'MON') = TO_CHAR(SYSDATE,'MON');
Needless to say, this doesn't work!!! I'm very new to SQL and APEX. I've also tried embedding SELECT STATEMENTS, as shown below, but still now dice (Trying to figure out out to calculate the TO_CHAR FROM DUAL and from TABLE_A for the "DATE" Column)
1. INSERT INTO TABLE_B (NAME_ID,Date,New_Date VALUES (
2. SELECT NAME_ID FROM TABLE_A,
3. ELECT DATE FROM TABLE_A,
4. SELECT TO_CHAR(DATE,'DD')||'-'||
5. SELECT TO_CHAR(DATE,'MON')||'-'||
6. SELECT TO_CHAR(SYSDATE,'YY') ) FROM
7. FROM NAMES
8 WHERE TO_CHAR(DATE,'MON') = TO_CHAR(SYSDATE,'MON');
Depending on the modifications I make I usually get the following two errors:
ORA-0933: SQL Command not properly ended (in the first example)
ORA-00936: Missing Expression (in the second example).
Appreciate any thoughts you all might have!!!
LEONHARK

Answer 1

So here's a question: are the different pieces of the day stored in the same column in Table A, or different columns? If they are the same, you can simplify a lot of your data copy procedure to:
  insert into TABLE_B (NAME_ID, SOME_DATE, NEW_DATE)
   values (select KEY_ID, to_date(ORIG_DATE,'DD-MM-YYYY') from TABLE_A
  where to_date(ORIG_DATE,'MM') = TO_DATE(SYSDATE,'MM'));If the dates are stored in individual fields in Table_A, use something like:
  insert into TABLE_B (NAME_ID, SOME_DATE, NEW_DATE)
   values (select KEY_ID, to_date(ORIG_DAY || '-' || ORG_MONTH || '-' || ORIG_YEAR,'DD-MM-YYYY') from TABLE_A
  where to_date(ORIG_DATE,'MM') = TO_DATE(SYSDATE,'MM'));An alternate for your where clause that uses a range of dates instead of a specific month is
  where to_date(ORIG_DATE,'DD-MM-YYYY') between TO_DATE('01-01-2007','MM-DD-YYYY') and TO_DATE('12-31-2007','MM-DD-YYYY');A couple of advantages: a date comparison is much faster than a string comparison and more accurate to what you want. Convert the strings to dates rather than the dates to strings. In my opinion, dealing with dates can be one of the biggest headaches for those learning SQL. There are a lot of good helps out there, but you will want to familiarize yourself with the TO_DATE() and TO_CHAR() functions, because you will use them a lot!
Also, store dates as DATE datatypes! Do NOT store them as text! You will save yourself a lot of headaches and your queries will run much faster if you use DATE datatypes.