plsql - Oracle: Insert rowtype data into another table

Question

I have one table called event, and created another global temp table tmp_event with the same columns and definition with event. Is it possible to insert records in event to tmp_event using this ?

DECLARE
   v_record event%rowtype;
BEGIN 
   Insert into tmp_event values v_record;
END;

There are too many columns in event table, I want to try this because I don't want to list all the columns.

Forget to mention: I will use this in the trigger, can this v_record be the object :new after insert on EVENT table ?

Answer 1

To insert one row-

DECLARE
   v_record event%rowtype;
BEGIN 
   SELECT * INTO v_record from event where rownum=1; --or whatever where clause
   Insert into tmp_event values v_record;
END;

Or a more elaborate version to insert all rows from event-

DECLARE
  TYPE t_bulk_collect_test_tab IS TABLE OF event%ROWTYPE;

  l_tab t_bulk_collect_test_tab;

  CURSOR c_data IS
    SELECT *
    FROM event;
BEGIN
  OPEN c_data;
  LOOP
    FETCH c_data
    BULK COLLECT INTO l_tab LIMIT 10000;
    EXIT WHEN l_tab.count = 0;

    -- Process contents of collection here.
    Insert into tmp_event values v_record;
  END LOOP;
  CLOSE c_data;
END;
/

In a trigger, yes it is possible but its like the chicken or the egg. You have to initialize every field of the rowtype with the :new column values like-

v_record.col1 := :new.col1;
v_record.col2 := :new.col2;
v_record.col3 := :new.col3;
....

Apparently, the PLSQL examples above cannot be used in a trigger since it would throw a mutating trigger error. And there is no other way for you to get the entire row in the trigger other than accessing each column separately as I explain above, so if you do all this why not directly use :new.col in the INSERT into temp_event itself, will save you a lot of work.

---

Also since you say it's a lot of work to mention all the columns, (in Oracle 11gR2) here's a quick way of doing that by generating the INSERT statement and executing it dynamically (although not tested for performance).

CREATE OR REPLACE TRIGGER event_air --air stands for "after insert of row"
AFTER INSERT ON EVENT
FOR EACH ROW
   L_query varchar2(2000);   --size it appropriately
BEGIN

   SELECT 'INSERT INTO tmp_event VALUES ('|| listagg (':new.'||column_name, ',') 
                                           WITHIN GROUP (ORDER BY column_name) ||')' 
     INTO l_query
     FROM all_tab_columns
    WHERE table_name='EVENT';

   EXECUTE IMMEDIATE l_query;

EXCEPTION
    WHEN OTHERS THEN
        --Meaningful exception handling here
END;