Question

The school has asked their estate manager Mr Rahul to maintain the data of all the labs in a table LAB. Rahul has created a table and entered data from 5 labs.

LAB NO	LAB_NAME	INCNCHARGE	CAPACITY	FLOOR
L001	CHEMISTRY	Daisy	20	I
L002	BIOLOGY	Venky	20	II
L003	MATH	Preeti	15	I
L004	LANGUAGE	Daisy	36	III
L005	COMPUTER	Mary	37	II

Based on the data given above answer the following questions:

(i) Identify the columns which can be considered as Candidate keys.

(ii) Write the degree and cardinality of the table.

(iii) Write the statements to:

      (a) Insert a new row with appropriate data.

      (b) Increase the capacity of all the labs by 10 students which are on
           the 'I' Floor.

                                     OR

(iii) Write the statements to:

        (a) Add a constraints PRIMARY KEY to the column LABNO in the table.

        (b) Delete the table LAB.

Answer 1

(i) Candidate key: LABNO

(ii) Degree: 5, Cardinality: 5

(iii)

1. Insert into LAB values("L006", "Physics", "John", 40, "III");
2. Update LAB set capacity = capacity + 10 where Floor = "I";

                          OR
(iii)

1. Alter table LAB ADD Primary Key(LABNO);
2. Drop table LAB;