Primary Key

PRIMARY KEYS In our relational system we want a way to make each row unique so we can tell them apart and ensure when we query the table we will be able to identify each row. To assist us in this we use a primary key—a column or combination of columns that contain...

Foreign Keys

RDBMS includes the word relational, indicating that the objects in our database should relate to one another. When we want to relate tables, at least one column of the same information should be included in the tables we want to relate. The primary reason I chose the...