fgets function for very large files

hi all, I have a csv file with more than 100,000 lines. I want to insert each line as a record in a database. but for the reason of very number of lines, I put a button with caption Next, when we click on it, 1000 line will insert into db and then again click next button and insert next 1000 line and.... is this good way? what do you recommend? and how can I do that? Thanks in advance, shahrzad