sqlite insert while drop complete duplicate

I am crawling some website and store the results in sqlite, since my crawling may repeat every month, but I don't want to store the duplicate results in my database, what should I do?

For example, the first time I will

insert into tableName(A, B, C, D, E) values(a,b,c,d,e) 

then my database will have this record, the next time I crawl this website, I will do the same, but I do not want to store the duplicate results, what is the best way I can do?

Besides, what to do if I am using MySQL?