The SELECT statement
reads records. It
does not create anything permanent.
select * from tblEVENEMENT
union all
select * from _dupEVENEMENT
... reads all the records in tblEVENEMENT, followed by all the records in _dupEVENEMENT and
displays them to you. All 672 (= 419 + 253) of them.
If you want to combine these into a new, single table, use the INSERT .. SELECT construct (which is how you
created the _dupEVENEMENT table in the first place).
Now you
might want to combine these together into a single table, but given that you created one from the other, that would probably give you duplicate keys ... and that would be Bad.
If you had a "main" table that you use the majority of the time and an "archived" table that you used rarely, in conjunction with the "main" table, then it would make sense to keep them
separate and only union them together when you actually need both. This
can given performance benefits in some cases (usually with very large Data).
Regards, Phill W.