Correct Answer: we can always fetch from one database and rewrite to another Here is a nice solution of it$db1 = mysql_connect("host","user","pwd") mysql_select_db("db1", $db1); $res1 = mysql_query("query",$db1);$db2 = mysql_connect("host","user","pwd") mysql_select_db("db2", $db2); $res2 = mysql_query("query",$db2);At this point you can only fetch records from you previous ResultSet, ie $res1 – But you cannot execute new query in $db1, even if you supply the link as because the link was overwritten by the new dbso at this point the following script will fail $res3 = mysql_query("query",$db1); //this will failSo how to solve that? take a look below $db1 = mysql_connect("host","user","pwd") mysql_select_db("db1", $db1); $res1 = mysql_query("query",$db1); $db2 = mysql_connect("host","user","pwd", true) mysql_select_db("db2", $db2); $res2 = mysql_query("query",$db2); So mysql_connect has another optional boolean parameter which indicates whether a link will be created or not, as we connect to the $db2 with this optional parameter set to 'true', so both link will remain live Now the following query will execute successfully $res3 = mysql_query("query",$db1);