Database Concept Quiz-6

Q51. Those field which can act as a primary key is called _________________

Q52. The relation EMPLOYEE has four attributes out of which EMPID and EMP_PHONE always take unique values. No two employees will have same phone number or same employee id. Hence, these two attributes are the _________________ keys as they both are candidates for __________________ key

Q53. Out of one or more candidate keys, the attribute chosen by the database designer to uniquely identify the tuples in a relation is called the _________________ of that relation.

Q54. The relation EMPLOYEE has four attributes out of which EMPID and EMP_PHONE are the candidates for Primary Key. The database designer choose EMP_ID as primary key then the remaining candidate key (EMP_PHONE) is called _____________________

Q55. Primary key consisting of more than one attribute is called _____________________.

Q56. Which of the following is most suitable primary key in table "STUDENT"?

Q57. A ____________ is used to represent the relationship between two relations.

Q58. A Foreign Key is an attribute whose value is derived from the _____________________ of another relation

Q59. A Foreign Key can take NULL values. (T/F)

Q60. A Primary Key can take NULL values. (T/F)