Furthermore, the unique constraint columns may be set to null. Data type and data length are the most fundamental integrity constraints applied to data in the database. Simply by specifying the data ...

Referential integrity (RI) is a method for ensuring the 'correctness' of data within a DBMS. People tend to oversimplify RI, stating that it is merely the identification of relationships between ...

A constraint checks the values you insert or update in a table against the conditions specified by the constraint. For example, a constraint could ensure that the value entered for the column GENDER ...