Differences between Primary Key and Foreign Key

Differences between Primary Key and Foreign Key

The main diference between primary key and the foreign key is that the primary key is a column or a set of columns that can be used to uniquely identify a row in a table while the foreign key is a column or a set of columns that refer to a primary key or a candidate key of another table.


Foreign key mainly provides a method to link information in several tables. Another difference is that a table can have a single primary key, but it can have multiple foreign keys that can reference different tables.