Question

I have a table that looks like this:

nid  vid  tid
1   2    3
2   2    4
3   2    4
4   2    3

I’d like to run some SQL that will take each one of those rows and create another based on it like so:

foreach row where vid=2, create a duplicate row where vid = 3

So I’ll end up with this:

   nid  vid  tid
    1   2    3
    2   2    4
    3   2    4
    4   2    3
    1   3    3
    2   3    4
    3   3    4
    4   3    3

The table is not that big (less than 500 rows, I think) and this is a one-time thing (so the code does not need to be amazingly optimized or anything). Thanks!

Answer 1

Could you do the following:

INSERT INTO TheTable(nid, vid,  nid)
SELECT nid, 3, nid
FROM TheTable
WHERE vid = 2

Two columns appear to have the same name, but the above should work. It takes the set of Vid = 2 elements, inserts them again but using Vid = 3.