sql server - Spring Batch Update: Insert only if does not exist otherwise update -

i need write batch update statement. able that. dont have primary key in table. there chances duplicate data sent database. want write batch update in such manner insert if data not exist. when data not exist, mean 3 columns of table can uniquely identify row. don't want make primary key using these 3 columns. there way can write batch update insert if data not exist otherwise update. have tried merge query not it. thanks

you can use itemprocessor filter out duplicated items query, return null if item present in database: objects pass processor can written itemwriter , sure there not duplicated