Extract a full timestamp (date included) from a Select query; Oracle

Question

So I am trying to insert multiples rows of data from one table to another. I have done this; however, I am having an issue with some of my columns, specifically my date colu

Answer 1

I wonder if you are making this problem more complicated than it needs to be.

There is the simple form of INSERT where you need need to provide a VALUES clause, but you can also insert the results of a SELECT statement directly.

So you could just write something like:

insert into dante2 (
  subcar, batch_id, silicon, temperature, sulphur, manganese, 
  phosphorus, start_pour, end_pour, sched_cast_date
)
SELECT 
  SUBCAR, BBP.BATCH_ID, SILICON, TEMPERATURE, SULPHUR, MANGANESE,
  pHOSPHORUS, START_POUR, END_POUR, SCHED_CAST_DATE
FROM 
  bof_chem_sample bcs, 
  bof_batch_pour bbp, 
  bof_celox_sample bofcs 
WHERE 
  bcs.SAMPLE_CODE= to_char('D1') and 
  bofcs.sample_code=bcs.sample_code and 
  bofcs.batch_id=bcs.batch_id and 
  bcs.batch_id = bbp.batch_id and 
  bofcs.temperature>0 AND 
  bbp.START_POUR>=to_date('01-JAN-2011', 'dd-mon-yyyy');

This will have the advantage of being much faster than your existing solution since each of the INSERT statements that you were running would take time to parse and execute but this has only single statement to run. It also runs in one step since you don't need to create the INSERT statements and all the types (like dates) are handled correctly.

However if you still need to create insert statements then you need to handle the data types. Strings and numbers are fine because Oracle knows what to do with them. dates are more of an issue because unless you use the to_char and to_date functions then you are relying on implicit conversion which will cause you mysterious problems like the ones you are experiencing. It's probably worth reading the Oracle documentation on implicit conversion to find out why it is bad.

As already mentioned by Cybernate, you would need to explicitly convert the date/time columns firstly to a character string (using to_char) that can then be converted back to a date by using to_date.