SQL Constraints. Sams Teach Yourself SQL in 24 Hours > Integrity Constraints. Integrity constraints are used to ensure accuracy and consistency of data in a relational database.
Data integrity is handled in a relational database through the concept of referential integrity. There are many types of integrity constraints that play a role in referential integrity (RI). Primary Key Constraints. [MCD] Modéliser un fournisseur pouvant être un client. SyBooks Online.