AdventureWorks Database: Return the count of employees by Name and Title, Name, and company total
SQL Query - AdventureWorks: Exercise-178 with Solution
178. From the following table write a query in SQL to return the count of employees by Name and Title, Name, and company total. Filter the results by department ID 12 or 14. For each row, identify its aggregation level in the Title column.
Sample table: HumanResources.Employee
businessentityid|nationalidnumber|loginid |jobtitle |birthdate |maritalstatus|gender|hiredate |salariedflag|vacationhours|sickleavehours|currentflag|rowguid |modifieddate |organizationnode|
----------------+----------------+----------------------------+----------------------------------------+----------+-------------+------+----------+------------+-------------+--------------+-----------+------------------------------------+-----------------------+----------------+
1|295847284 |adventure-works\ken0 |Chief Executive Officer |1969-01-29|S |M |2009-01-14|true | 99| 69|true |f01251e5-96a3-448d-981e-0f99d789110d|2014-06-30 00:00:00.000|/ |
2|245797967 |adventure-works\terri0 |Vice President of Engineering |1971-08-01|S |F |2008-01-31|true | 1| 20|true |45e8f437-670d-4409-93cb-f9424a40d6ee|2014-06-30 00:00:00.000|/1/ |
3|509647174 |adventure-works\roberto0 |Engineering Manager |1974-11-12|M |M |2007-11-11|true | 2| 21|true |9bbbfb2c-efbb-4217-9ab7-f97689328841|2014-06-30 00:00:00.000|/1/1/ |
4|112457891 |adventure-works\rob0 |Senior Tool Designer |1974-12-23|S |M |2007-12-05|false | 48| 80|true |59747955-87b8-443f-8ed4-f8ad3afdf3a9|2014-06-30 00:00:00.000|/1/1/1/ |
5|695256908 |adventure-works\gail0 |Design Engineer |1952-09-27|M |F |2008-01-06|true | 5| 22|true |ec84ae09-f9b8-4a15-b4a9-6ccbab919b08|2014-06-30 00:00:00.000|/1/1/2/ |
6|998320692 |adventure-works\jossef0 |Design Engineer |1959-03-11|M |M |2008-01-24|true | 6| 23|true |e39056f1-9cd5-478d-8945-14aca7fbdcdd|2014-06-30 00:00:00.000|/1/1/3/ |
7|134969118 |adventure-works\dylan0 |Research and Development Manager |1987-02-24|M |M |2009-02-08|true | 61| 50|true |4f46deca-ef01-41fd-9829-0adab368e431|2014-06-30 00:00:00.000|/1/1/4/ |
8|811994146 |adventure-works\diane1 |Research and Development Engineer |1986-06-05|S |F |2008-12-29|true | 62| 51|true |31112635-663b-4018-b4a2-a685c0bf48a4|2014-06-30 00:00:00.000|/1/1/4/1/ |
9|658797903 |adventure-works\gigi0 |Research and Development Engineer |1979-01-21|M |F |2009-01-16|true | 63| 51|true |50b6cdc6-7570-47ef-9570-48a64b5f2ecf|2014-06-30 00:00:00.000|/1/1/4/2/ |
10|879342154 |adventure-works\michael6 |Research and Development Manager |1984-11-30|M |M |2009-05-03|true | 16| 64|true |eaa43680-5571-40cb-ab1a-3bf68f04459e|2014-06-30 00:00:00.000|/1/1/4/3/ |
-- more --
Sample table: HumanResources.EmployeeDepartmentHistory
businessentityid|departmentid|shiftid|startdate |enddate |modifieddate |
----------------+------------+-------+----------+----------+-----------------------+
1| 16| 1|2009-01-14| |2009-01-13 00:00:00.000|
2| 1| 1|2008-01-31| |2008-01-30 00:00:00.000|
3| 1| 1|2007-11-11| |2007-11-10 00:00:00.000|
4| 1| 1|2007-12-05|2010-05-30|2010-05-28 00:00:00.000|
4| 2| 1|2010-05-31| |2010-05-30 00:00:00.000|
5| 1| 1|2008-01-06| |2008-01-05 00:00:00.000|
6| 1| 1|2008-01-24| |2008-01-23 00:00:00.000|
-- more --
Sample table: HumanResources.Department
departmentid|name |groupname |modifieddate |
------------+--------------------------+------------------------------------+-----------------------+
1|Engineering |Research and Development |2008-04-30 00:00:00.000|
2|Tool Design |Research and Development |2008-04-30 00:00:00.000|
3|Sales |Sales and Marketing |2008-04-30 00:00:00.000|
4|Marketing |Sales and Marketing |2008-04-30 00:00:00.000|
5|Purchasing |Inventory Management |2008-04-30 00:00:00.000|
6|Research and Development |Research and Development |2008-04-30 00:00:00.000|
7|Production |Manufacturing |2008-04-30 00:00:00.000|
8|Production Control |Manufacturing |2008-04-30 00:00:00.000|
9|Human Resources |Executive General and Administration|2008-04-30 00:00:00.000|
10|Finance |Executive General and Administration|2008-04-30 00:00:00.000|
11|Information Services |Executive General and Administration|2008-04-30 00:00:00.000|
12|Document Control |Quality Assurance |2008-04-30 00:00:00.000|
13|Quality Assurance |Quality Assurance |2008-04-30 00:00:00.000|
14|Facilities and Maintenance|Executive General and Administration|2008-04-30 00:00:00.000|
15|Shipping and Receiving |Inventory Management |2008-04-30 00:00:00.000|
16|Executive |Executive General and Administration|2008-04-30 00:00:00.000|
Sample Solution:
-- This SQL query retrieves information about employee counts grouped by department and job title,
-- with additional logic for displaying total counts at various levels.
SELECT D.Name -- Selecting the department name.
,CASE
WHEN GROUPING(D.Name, E.JobTitle) = 0 THEN E.JobTitle -- When not grouping by department or job title, display the job title.
WHEN GROUPING(D.Name, E.JobTitle) = 1 THEN CONCAT('Total :', D.Name) -- When grouping by department but not by job title, display the total count for the department.
WHEN GROUPING(D.Name, E.JobTitle) = 3 THEN 'Company Total:' -- When grouping by neither department nor job title, display the total count for the company.
ELSE 'Unknown' -- Display 'Unknown' for other cases.
END AS "Job Title" -- Alias for the computed column.
,COUNT(E.BusinessEntityID) AS "Employee Count" -- Counting the number of employees in each group.
FROM HumanResources.Employee E -- Main table: Employee
INNER JOIN HumanResources.EmployeeDepartmentHistory DH -- Joining with EmployeeDepartmentHistory table.
ON E.BusinessEntityID = DH.BusinessEntityID
INNER JOIN HumanResources.Department D -- Joining with Department table.
ON D.DepartmentID = DH.DepartmentID
WHERE DH.EndDate IS NULL -- Filtering to include only active employees.
AND D.DepartmentID IN (12,14) -- Filtering departments by DepartmentID.
GROUP BY ROLLUP(D.Name, E.JobTitle); -- Using ROLLUP for grouping, which generates subtotals.
Explanation:
- The query retrieves employee counts grouped by department and job title.
- It includes logic to display subtotals and total counts at different levels of grouping.
- The CASE statement determines the content of the "Job Title" column based on the grouping level.
- COUNT(E.BusinessEntityID) calculates the number of employees in each group.
- The ROLLUP function generates subtotals for different levels of grouping.
Sample Output:
name |Job Title |Employee Count|
--------------------------+-----------------------------------+--------------+
|Company Total: | 12|
Document Control |Control Specialist | 2|
Facilities and Maintenance|Janitor | 4|
Facilities and Maintenance|Facilities Manager | 1|
Document Control |Document Control Assistant | 2|
Document Control |Document Control Manager | 1|
Facilities and Maintenance|Maintenance Supervisor | 1|
Facilities and Maintenance|Facilities Administrative Assistant| 1|
Facilities and Maintenance|Total :Facilities and Maintenance | 7|
Document Control |Total :Document Control | 5|
SQL AdventureWorks Editor:
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