I have a very large single-table database of articles that I want to convert to a multi-table, relational database.
The existing single-table database contains fields for article author, article source, and article category, where several 'author', 'source', and 'category' IDs repeat dozens of times for hundreds of different articles.
I want to create seperate tables for author, source, and category and populate the new tables by extracting data from the original single-table database by unique ID field.
I figured out how to use INSERT and SELECT to pull data in new tables, but can't figure out how to pull only a single instance of a unique author, source, and category to create master reference tables for author/source/category.
Any assistance would be much appreciated.
Thanks in advance.