In an inventory management system implemented at a trading corporation, there are several tables designed to hold all the information. Amongst these, the following two tables hold information on which items are supplied by which suppliers, and which warehouse keeps which items along with the stock-level of these items.

Supply = (supplierid, itemcode)
Inventory = (itemcode, warehouse, stocklevel)

For a specific information required by the management, following SQL query has been written

Select distinct STMP.supplierid 
From Supply as STMP 
Where not unique (Select ITMP.supplierid 
    From Inventory, Supply as ITMP 
    Where STMP.supplierid = ITMP.supplierid 
    And ITMP.itemcode = Inventory.itemcode 
    And Inventory.warehouse = 'Nagpur');

For the warehouse at Nagpur, this query will find all suppliers who

Consider two tables in a relational database with columns and rows as follows:

 Table: Student

Roll_no	Name	Dept_id
1	ABC	1
2	DEF	1
3	GHI	2
4	JKL	3

 Table: Department

Dept_id	Dept_name
1	A
2	B
3	C

Roll_no is the primary key of the Student table, Dept_id is the primary key of the Department table and Studetn.Dept_id is a foreign key from
Department. Dept_id.

What will happen if we try to execute the following two SQL statements?

(i) update Student set Dept_id = Null where Roll_no =1
(ii) update Department set Dept_id = Null where Dept_id =1

A relational database contains two table student and department in which student table has columns roll_no, name and dept_id and department table has columns dept_id and detp_name. the following insert statements were executed successfully to populate the empty tables:

 Insert into department values (1, ‘Mathematics’)
 Insert into department values (2, ‘Physics’)
 Insert into student values (1, ‘Navin’,1)
 Insert into student values (2, ‘Mukesh’,2)
 Insert into student values (3, ‘Gita’,1)

How many rows and columns will be retrieved by the following SQL statement?

Select * from student, department;

The employee information in a company is stored in the relation

Employee (name, sex, salary, deptName)

Consider the following SQL query

  Select deptName
  From Employee
  Where sex = ‘M’
  Group by deptName
  Having avg(salary) >
  (Select avg (salary) From Employee);

It returns the names of the department in which