Pro rata basis bonus distribution using setup table - sql

Question

CREATE TABLE #empInfo(emp_id INT, dept_id INT, salary INT)
CREATE TABLE #empBonus(dep_id INT, emp_id INT, bonus INT)
I have above two tables for Employee and Bonus, where I will allocate bonus for the employees in bonus table every year but in example we are going to do it for a year only so the year column is not given.
INSERT INTO #empInfo VALUES
(111, 100, 5000),
(112, 100, 4000),
(113, 100, 4000),
(114, 100, 3500),
(115, 100, 4500),
(116, 100, 3000),
(114, 200, 3500),
(115, 200, 4500),
(116, 200, 3000),
(114, 300, 3500),
(115, 300, 3500),
(116, 300, 3500)
INSERT INTO #empBonus VALUES
(100, 111, 1000),
(100, NULL, 4000),
(100, 111, 500),
(100, NULL, 4000),
(100, 113, 700),
(200, 114, 600),
(200, NULL, 1600),
(300, 116, 900)
Above, If employee id defined in empBonus table then the bonus should allocated for that employee and if null that means bonus for all employees whose are not listed in the empBonus and will get bonus according to their salary.
we can define bonus for multiple employees and it can be multiple for same employee, in this case we have to sum total bonus and perform operation accordingly. Same case is for NULL.
For example, Base on formula given below, I have done below calculation in the EXCEL for easy understanding and in SQL I am trying with OUTER APPLY but not getting what I want from single query ?
--Formula = bonus*salary/totSalary(of respective group or employee)
DeptID EmpID TotBonus Salary TotSalary Bonus
100 111 1500 5000 5000 1500.00000000000
100 112 8000 4000 15000 2133.33333333333
100 113 700 4000 4000 700.00000000000
100 114 8000 3500 15000 1866.66666666666
100 115 8000 4500 15000 2400.00000000000
100 116 8000 3000 15000 1600.00000000000
200 114 600 3500 3500 600.00000000000
200 115 1600 4500 7500 960.00000000000
200 116 1600 3000 7500 640.00000000000
300 114 0 3500 7000 0.00000000000
300 115 0 3500 7000 0.00000000000
300 116 900 3500 3500 900.00000000000
Any help will be appreciated, thanks in advance :)

Answer 1

Here is one way using FULL OUTER JOIN and SUM() OVER() Window aggregate
;WITH cte
AS (SELECT ei.emp_id,ei.dept_id, eb.dep_id,
bonus = COALESCE(bonus, Max(CASE WHEN eb.emp_id IS NULL THEN bonus END)
OVER( partition BY COALESCE(ei.dept_id, eb.dep_id) )),
salary = Cast(salary AS NUMERIC(22, 6)),
TotSalary= Iif(eb.emp_id IS NULL, Sum(CASE WHEN eb.emp_id IS NULL THEN salary END)
OVER(partition by ei.dept_id), salary)
FROM #empInfo ei
FULL OUTER JOIN (SELECT bonus= Sum(bonus),
dep_id,
emp_id
FROM #empBonus
GROUP BY dep_id,
emp_id) eb
ON ei.dept_id = eb.dep_id
AND eb.emp_id = ei.emp_id)
SELECT emp_id,
bonus,
salary,
TotSalary,
( bonus * salary ) / NULLIF(TotSalary, 0)
FROM cte
WHERE emp_id IS NOT NULL
Result:
+--------+-------+-------------+-----------+--------------------+
| emp_id | bonus | salary | TotSalary | Bonus Distribution |
+--------+-------+-------------+-----------+--------------------+
| 111 | 1500 | 5000.000000 | 5000 | 1500.00000000000 |
| 112 | 8000 | 4000.000000 | 19000 | 1684.21052631578 |
| 113 | 8000 | 4000.000000 | 19000 | 1684.21052631578 |
| 114 | 8000 | 3500.000000 | 19000 | 1473.68421052631 |
| 115 | 8000 | 4500.000000 | 19000 | 1894.73684210526 |
| 116 | 8000 | 3000.000000 | 19000 | 1263.15789473684 |
+--------+-------+-------------+-----------+--------------------+

Answer 2

Well, that was a good challenge for me.
First, create a cte is to calculate the TotSalary column:
;With cteTotalSalary as
(
-- select total salary for employees that are in the bonus table
SELECT e.emp_id, dept_id, Salary, Salary As TotSalary
FROM #empInfo e
INNER JOIN #empBonus b ON e.dept_id = b.dep_id AND e.emp_id = b.emp_id
UNION
-- select total salary for employees that are in NOT the bonus table
SELECT e.emp_id, dept_id, Salary, SUM(Salary) OVER(PARTITION BY dept_id) As TotSalary
FROM #empInfo e
WHERE EXISTS (
SELECT 1
FROM #empBonus b
WHERE e.dept_id = b.dep_id
AND b.emp_id IS NULL
)
AND NOT EXISTS
(
SELECT 1
FROM #empBonus b
WHERE e.dept_id = b.dep_id
AND e.emp_id = b.emp_id
)
)
Then, query this cte twice with a union to get both types of bonuses (employee bonus and department bonus)
-- Get the bonus of the employess that exists in the empBonus table
SELECT c.emp_id, dept_id, SUM(Bonus) OVER(PARTITION BY c.emp_id) as Bonus, Salary, TotSalary, CAST(SUM(CAST(Bonus as decimal)) OVER(PARTITION BY c.emp_id) as decimal) as [Bonus Distribution]
FROM cteTotalSalary c
INNER JOIN #empBonus b ON c.dept_id = b.dep_id AND c.emp_id = b.emp_id
UNION
-- Get the bonus of the employees that does not exists in the empBonus table
SELECT c.emp_id, dept_id, SUM(Bonus) OVER(PARTITION BY c.emp_id), Salary, TotSalary, SUM(CAST(Bonus as decimal) * Salary / TotSalary) OVER(PARTITION BY c.emp_id)
FROM cteTotalSalary c
INNER JOIN #empBonus b ON c.dept_id = b.dep_id AND b.emp_id IS NULL
AND NOT EXISTS (
SELECT 1
FROM #empBonus b
WHERE c.dept_id = b.dep_id
AND c.emp_id = b.emp_id
)
Results:
emp_id dept_id Bonus Salary TotSalary Bonus Distribution
111 100 1500 5000 5000 1500.000000000
112 100 8000 4000 19000 1684.210526314
113 100 8000 4000 19000 1684.210526314
114 100 8000 3500 19000 1473.684210526
115 100 8000 4500 19000 1894.736842104
116 100 8000 3000 19000 1263.157894736
You can see it in action here