Aug 25, 2021
1 min read
Into the data: Day 8
On Day 8, I learned about relational databases and I learned about primary keys, foreign keys and composite key. A primary key is something that has unique value and can only appear once in that particular column.
As for a foreign key, it is that same primary key that appears in a different column where it is not the primary key and finally for the composite key, it is a mix of primary keys resulting in a unique key.
