multi_query update from table1 to table2 after on-click complete update table1 PHP

multi_query update from table1 to table2 after on-click complete update
table1 PHP

Looking to use a P.H.P code to update user from table 1 into table 2 if no
user if user in in table 2 would like to be able to do on click code and
then update table 1 with data from table 2 ??? i have some code i think
could work