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Execution of the above query will produce the output shown in Table 4.28.
COUNT(*)
5
Table 4.28 Count of employees earning 75000 or more
To execute the above statement, the function COUNT() finds the number of tuples in the EMPLOYEE table whose
Salary attribute has value 75000 or more.
Note that the above output would look much nicer if the SQL output table were named EmployeeCount instead
of COUNT(*). For this pur[pose,SQL provides an AS clause which renames the output table. The following SQL
statement achieves this.
SELECT COUNT(*) AS EmployeeCount
FROM EMPLOYEE
WHERE Salary >= 75000;
AS: Renames the Output Column for ease of display/ referencing.
The above SQL statement introduces a name (EmployeeCount) for the output column. A name defined
using the AS clause is known as an alias. Execution of the above statement will produce the output shown in
Table 4.29.
EmployeeCount
5
Table 4.29 Count of employees as EmployeeCount
SUM(attribute-name)
Returns sum of the attribute values satisfying condition(s) in WHERE clause.
2. SUM(): The function SUM() is used to compute the sum of attribute values (based on the selection criterion
mentioned in WHERE clause, if specified).
For example, to display the total salary of all employees, the following query may be used:
SELECT SUM(Salary) AS Total_Salary
FROM EMPLOYEE;
Execution of the above statement will produce the output shown in Table 4.30.
Total_Salary
795000
Table 4.30 Total salary of all employees
3. MAX(): MAX() function finds the maximum of a set of values.
Query: Display the maximum salary from the EMPLOYEE table.
Solution:
SELECT MAX(Salary) AS Maximum_Salary
FROM EMPLOYEE;
162 Touchpad Informatics Practices-XII

