Write the different types of constraints and their functions.

Consider the following employee table. Write SQL commands for the qtns.(i) to (v).

EMP CODE	NAME	DESIG	PAY	ALLOWANCE
S1001	Hariharan	Supervisor	29000	12000
P1002	Shaji	Operator	10000	5500
P1003	Prasad	Operator	12000	6500
C1004	Manjima	Clerk	8000	4500
M1005	Ratheesh	Mechanic	20000	7000

(i) To display the details of all employees in descending order of pay.
(ii) To display all employees whose allowance is between 5000 and 7000.
(iii) To remove the employees who are mechanic.
(iv) To add a new row.
(v) To display the details of all employees who are operators.

What are the components of SQL? Write the commands in each.

Construct the following SQL statements in the student table-
(i) SELECT statement using GROUP BY clause.
(ii) SELECT statement using ORDER BY clause.

Write a SQL statement to create a table for employee having any five fields and create a table constraint for the employee table.