# UGCNET-Dec2012-III: 70

875 views

Referential integrity is directly related to

1. Relation key
2. Foreign key
3. Primary key
4. Candidate key

recategorized

1 vote

Referential integrity is a database concept that ensures that relationships between tables remain consistent. When one table has a foreign key to another table, the concept of referential integrity states that you may not add a record to the table that contains the foreign key unless there is a corresponding record in the linked table. It also includes the techniques known as cascading update and cascading delete, which ensure that changes made to the linked table are reflected in the primary table.

Hence,Option(B)Foreign key .

Ans B)Referential Integrity ---> Foreign key (one or more keys of one tables are derived from some other tables primary or unique key)

so that it can    not have any invalid(non-existent) value. It can have either matched value of some primary or unique key of derived table or NULL

Entity Integrity ---->Primary key (It can have only unique and NOT NULL  values i.e duplicates and NULL (unknown )  are not allowed

## Related questions

1 vote
1
2.4k views
The third normal form is based on the concept of_____ Closure Dependency Transitive Dependency Normal Dependency Functional Dependency
1 vote
If a relation with a Schema R is decomposed into two relations $R_1$ and $R_2$ such that $(R_1 \cup R_2) = R_1$ then which one of the following is to be satisfied for a lossless joint decomposition ($\rightarrow$ ... $R_1 \cap R_2 \rightarrow R_2$ $(R_1 \cap R_2) \rightarrow R_1 \text{ and } R_1 \cap R_2 \rightarrow R_2$
Let $\theta(x, y, z)$ be the statement “x+y=z” and let there be two quantification given as $\forall x \forall y \exists z \theta (x,y,z)$ $\exists z \forall x \forall y \theta (x,y,z)$ where x, y, z are real numbers, then which one of the following is correct? I is true and II is true I is true and II is false I is false and II is true I is false and II is false