Correct Answer - Option 3 : Assertion
Domain constraints, functional dependency, and referential integrity are special forms of Assertion
Domain constraints: example (age cannot be negative)
functional dependency: Dependency of attributes in relations
Foreign key
- A foreign key means that values in one table must also appear in another table. T
- he referenced table is called the parent table while the table with the foreign key is called the child table.
- The foreign key in the child table will generally reference a primary key in the parent table.
Primary key
- A primary key is a specific choice of a minimal set of attributes (columns) that uniquely specify a tuple (row) in a relation (table). Primary key cannot accept null values and there can be only one primary key constraint for one table.
Referential integrity constraints
- In a relational database, a referential integrity constraint is specified between two tables with the help of a foreign key.
- In the Referential integrity constraints, if a foreign key in Table 1 refers to the primary Key of Table 2, then every value of the Foreign Key in Table 1 must be null or be available in Table 2.
