Now that we have the information about the artist separated from the album information, we can redesign the table of information for the CDs themselves. I've highlighted the column where the ArtistName string was replaced with a primary key from the table containing the related data record. In database parlance, this is typically called a foreign key . The two database tables are now related by the ArtistID key field. The database relationship we created in the previous section is simple, but it is an example of the most common type of database relationship.
Numbers are always better than text.
Any single field can be used as a key in n other tables. Fields that are used for relationships should typically be indexed for performance. After that, we'll move back to SQL proper and cover using the JOIN keyword to create SQL statements that use database relationships. Until then, feel free to send me your comments, questions, and feedback. Read more from aboutSQL .