MySQL Aggregate Function Exercises: Get the total salary, maximum, minimum, average salary of employees, for department ID 90 only
MySQL Aggregate Function: Exercise-12 with Solution
Write a query to get the total salary, maximum, minimum, average salary of employees (job ID wise), for department ID 90 only.
Sample table: employees
+-------------+-------------+-------------+----------+--------------------+------------+------------+----------+----------------+------------+---------------+ | EMPLOYEE_ID | FIRST_NAME | LAST_NAME | EMAIL | PHONE_NUMBER | HIRE_DATE | JOB_ID | SALARY | COMMISSION_PCT | MANAGER_ID | DEPARTMENT_ID | +-------------+-------------+-------------+----------+--------------------+------------+------------+----------+----------------+------------+---------------+ | 100 | Steven | King | SKING | 515.123.4567 | 1987-06-17 | AD_PRES | 24000.00 | 0.00 | 0 | 90 | | 101 | Neena | Kochhar | NKOCHHAR | 515.123.4568 | 1987-06-18 | AD_VP | 17000.00 | 0.00 | 100 | 90 | | 102 | Lex | De Haan | LDEHAAN | 515.123.4569 | 1987-06-19 | AD_VP | 17000.00 | 0.00 | 100 | 90 | | 103 | Alexander | Hunold | AHUNOLD | 590.423.4567 | 1987-06-20 | IT_PROG | 9000.00 | 0.00 | 102 | 60 | | 104 | Bruce | Ernst | BERNST | 590.423.4568 | 1987-06-21 | IT_PROG | 6000.00 | 0.00 | 103 | 60 | | 105 | David | Austin | DAUSTIN | 590.423.4569 | 1987-06-22 | IT_PROG | 4800.00 | 0.00 | 103 | 60 | | 106 | Valli | Pataballa | VPATABAL | 590.423.4560 | 1987-06-23 | IT_PROG | 4800.00 | 0.00 | 103 | 60 | | 107 | Diana | Lorentz | DLORENTZ | 590.423.5567 | 1987-06-24 | IT_PROG | 4200.00 | 0.00 | 103 | 60 | | 108 | Nancy | Greenberg | NGREENBE | 515.124.4569 | 1987-06-25 | FI_MGR | 12000.00 | 0.00 | 101 | 100 | ......... | 206 | William | Gietz | WGIETZ | 515.123.8181 | 1987-10-01 | AC_ACCOUNT | 8300.00 | 0.00 | 205 | 110 | +-------------+-------------+-------------+----------+--------------------+------------+------------+----------+----------------+------------+---------------+
Code:
-- Calculating various statistics for salaries of employees in department 90, grouped by job_id
SELECT job_id, SUM(salary), AVG(salary), MAX(salary), MIN(salary)
-- Selecting data from the employees table
FROM employees
-- Filtering the result set to include only rows where the department_id is '90'
WHERE department_id = '90'
-- Grouping the result set by job_id
GROUP BY job_id;
Explanation:
- This SQL query calculates various statistics (sum, average, maximum, minimum) for the salaries of employees in department 90, grouped by job title (job_id).
- The SELECT statement retrieves the job_id column along with the sum, average, maximum, and minimum salaries for each job title.
- The FROM clause specifies the employees table from which the data is being selected.
- The WHERE clause filters the result set to include only rows where the department_id is '90', ensuring that only employees from department 90 are considered.
- The GROUP BY clause groups the result set by the job_id column, allowing for the aggregation of salary statistics for each job title.
Relational Algebra Expression:
Relational Algebra Tree:
Pictorial Presentation of the above query
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MySQL Code Editor:
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