AdventureWorks Database: Cross product of BusinessEntityID and Department columns

SQL Query - AdventureWorks: Exercise-165 with Solution

165. From the following tables write a query in SQL to return the cross product of BusinessEntityID and Department columns.

The following example returns the cross product of the two tables Employee and Department in the AdventureWorks2019 database. A list of all possible combinations of BusinessEntityID rows and all Department name rows are returned.

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 --

Click to view Full table

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|

Click to view Full table

Sample Solution:

-- This SQL query selects the BusinessEntityID from the Employee table and the Name of each department from the Department table, performing a cross join between the two tables.
-- Selecting BusinessEntityID from the Employee table and assigning the alias 'e' to the table.
SELECT e.BusinessEntityID, 
-- Selecting the Name column from the Department table and assigning the alias 'Department' to the column.
       d.Name AS Department  
-- Performing a cross join between the Employee table (aliased as 'e') and the Department table (aliased as 'd').
FROM HumanResources.Employee AS e  
CROSS JOIN HumanResources.Department AS d  
-- Ordering the result set by BusinessEntityID and Department name in ascending order.
ORDER BY e.BusinessEntityID, d.Name ;

Explanation:

• The query retrieves the BusinessEntityID of each employee along with the name of each department.
• A cross join is used to generate a Cartesian product between the Employee and Department tables, combining each row from the Employee table with every row from the Department table.
• Since there is no specified join condition (like ON clause), a cross join results in every possible combination of rows from both tables.
• The result set contains all possible combinations of Employee IDs and Department names.
• Finally, the result set is ordered by BusinessEntityID and Department name in ascending order.

Sample Output:

businessentityid|department                |
----------------+--------------------------+
               1|Document Control          |
               1|Engineering               |
               1|Executive                 |
               1|Facilities and Maintenance|
               1|Finance                   |
               1|Human Resources           |
               1|Information Services      |
               1|Marketing                 |
               1|Production                |
               1|Production Control        |
               1|Purchasing                |
               1|Quality Assurance         |
               1|Research and Development  |
               1|Sales                     |
               1|Shipping and Receiving    |
...	

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