Database Constraints
A relational database is a collection of data items organized as a set of formally described tables from which data can be accessed easily. A relational database is created using the relational model. The software used in a relational database is called a relational database management system (RDBMS). A relational database is the predominant choice in storing data, over other models like the hierarchical database model or the network model. It consists of n number tables and each table has its own primary key.
The relational database was first defined in June 1970 by Edgar Codd, of IBM's San Jose Research Laboratory.
Read more about Database Constraints: Terminology, Relations or Tables, Base and Derived Relations, Constraints, Relational Operations, Normalization, Relational Database Management Systems
Famous quotes containing the word constraints:
“Play is a major avenue for learning to manage anxiety. It gives the child a safe space where she can experiment at will, suspending the rules and constraints of physical and social reality. In play, the child becomes master rather than subject.... Play allows the child to transcend passivity and to become the active doer of what happens around her.”
—Alicia F. Lieberman (20th century)