I have 2 identical tables in 2 different databases that reside on the same server. What would be the best way to copy data from table to another?
Just to elaborate slightly on OMG Ponies' answer, you can use any WHERE clause, like so:
WHERE
INSERT INTO db1.tablename SELECT * FROM db2.tablename src WHERE src.lastlogin >= '2013-10-31 07:00:00'