Untitled

Check against multiple duplicate records
CREATE TABLE `test` (
  `A` varchar(19) NOT NULL,
  `B` varchar(9) NOT NULL,
  KEY `A` (`A`),
  KEY `B` (`B`)
) ENGINE=InnoDB;

$names="";
  for(each element){
      $names.=$val.", ";
  //remove last comma ","

select * from myTable where username in ($names);

insert into myTable (username, address, otherstuff)
values("henry", "35 skid", "who knows")
ON DUPLICATE KEY UPDATE
otherstuff = values(otherstuff);