Sign up
Please tick the below box to proceed
I agree (or if I am under 13 my parent or guardian agrees on my behalf) to the terms and conditions of use and that:
- My test statistics may be published on the site leaderboard against my username
- My teacher(s) can review my test scores
- I can receive feedback on my tests from my teacher(s)
Please tick this box to proceed
Already have an account? Sign in
Preview lessons, content and tests
Computer Science & Programming solved. All in one platform.
1. To trial the platform and take tests, please take a few seconds to SIGN UP and SET UP FREE.2. Searching for something specific? See our text overview of all tests. Scroll right for levels, and lists. 3. Student and Teacher User Guides | Schemes of Work | Real Teacher use Videos |
Join 36000+ teachers and students using TTIO.
Referential Integrity
Referential integrity refers to the accuracy and consistency of data within a relationship. In relationships, data is linked between two or more tables. This is achieved by having the foreign key (in the associated table) reference a primary key value (in the primary – or parent – table).
(Above) An example of a database that has not enforced referential integrity. In this example, there is a foreign key (artist_id) value in the album table that references a non-existent artist — in other words there is a foreign key value with no corresponding primary key value in the referenced table.
Alternative Explanation
Referential integrity refers to the accuracy and consistency of data within a relationship.
In relationships, data is linked between two or more tables. This is achieved by having the foreign key (in the associated table) reference a primary key value (in the primary – or parent – table). Because of this, we need to ensure that data on both sides of the relationship remain intact.
So, referential integrity requires that, whenever a foreign key value is used it must reference a valid, existing primary key in the parent table.