Friday, 28 June 2013
year 13 m1
Referential integrity enforces that the relationships between tables relevant, consistent and valid, and that no invalid links exist between tables. Foreign keys allow you to define relationships between tables in a database. A primary key is unique and is used to keep track specific data when there is more than one of the same piece of data, for example, when there are two books of the same name in a library, the bar codes would be of each of these would be unique. Searching for the unique bar code in the database would be quicker and easier than searching for the genre.
Subscribe to:
Post Comments (Atom)
www. M1. A excellent piece of work. You have clearly explained the purpose of primary and foreign keys here, and the concept of referential integrity is described accurately.
ReplyDeleteebi. you add a couple of screenshots to help visual learners to understand the concept.