This is personal study note Copyright and original reference: https://www.youtube.com/watch?v=aS9FoCNlt3o&list=PLuHgQVnccGMDF6rHsY9qMuJMd295Yk4sa ================================================================================ topic.title.MySQL represents 1st row as primary key author_name, author_profile depend on "author_id" "author_id" depends on "title" This is "transitive dependencies" ================================================================================ Copy "transitive dependencies" part and create author table And create topic table with "author_id" And remove duplicate