MySQL Northwind database, Products table: Count current and discontinued products

MySQL Northwind database: Exercise-9 with Solution

9. Write a MySQL query to count current and discontinued products.

Code:

-- This SQL query counts the number of occurrences of ProductName in the Products table, grouping the counts by the Discontinued column.

SELECT Count(ProductName) -- Counts the number of occurrences of ProductName
FROM Products -- Specifies the table from which to retrieve data, in this case, the Products table
GROUP BY Discontinued; -- Groups the counts by the values in the Discontinued column

Explanation:

• The SELECT statement counts the number of occurrences of ProductName in the Products table.
• The GROUP BY clause groups the counts by the values in the Discontinued column.

Relational Algebra Expression:

Relational Algebra Tree:

Structure of Products table:

Sample records of Products Table:

+-----------+---------------------------------+------------+------------+---------------------+-----------+--------------+--------------+--------------+--------------+
| ProductID | ProductName                     | SupplierID | CategoryID | QuantityPerUnit     | UnitPrice | UnitsInStock | UnitsOnOrder | ReorderLevel | Discontinued |
+-----------+---------------------------------+------------+------------+---------------------+-----------+--------------+--------------+--------------+--------------+
|         1 | Chai                            |          1 |          1 | 10 boxes x 20 bags  |   18.0000 |           39 |            0 |           10 |              |
|         2 | Chang                           |          1 |          1 | 24 - 12 oz bottles  |   19.0000 |           17 |           40 |           25 |              |
|         3 | Aniseed Syrup                   |          1 |          2 | 12 - 550 ml bottles |   10.0000 |           13 |           70 |           25 |              |
|         4 | Chef Anton's Cajun Seasoning    |          2 |          2 | 48 - 6 oz jars      |   22.0000 |           53 |            0 |            0 |              |
|         5 | Chef Anton's Gumbo Mix          |          2 |          2 | 36 boxes            |   21.3500 |            0 |            0 |            0 | ☺            |
|         6 | Grandma's Boysenberry Spread    |          3 |          2 | 12 - 8 oz jars      |   25.0000 |          120 |            0 |           25 |              |
|         7 | Uncle Bob's Organic Dried Pears |          3 |          7 | 12 - 1 lb pkgs.     |   30.0000 |           15 |            0 |           10 |              |
|         8 | Northwoods Cranberry Sauce      |          3 |          2 | 12 - 12 oz jars     |   40.0000 |            6 |            0 |            0 |              |
|         9 | Mishi Kobe Niku                 |          4 |          6 | 18 - 500 g pkgs.    |   97.0000 |           29 |            0 |            0 | ☺            |
|        10 | Ikura                           |          4 |          8 | 12 - 200 ml jars    |   31.0000 |           31 |            0 |            0 |              |
|        11 | Queso Cabrales                  |          5 |          4 | 1 kg pkg.           |   21.0000 |           22 |           30 |           30 |              |
|        12 | Queso Manchego La Pastora       |          5 |          4 | 10 - 500 g pkgs.    |   38.0000 |           86 |            0 |            0 |              |
|        13 | Konbu                           |          6 |          8 | 2 kg box            |    6.0000 |           24 |            0 |            5 |              |
|        14 | Tofu                            |          6 |          7 | 40 - 100 g pkgs.    |   23.2500 |           35 |            0 |            0 |              |
|        15 | Genen Shouyu                    |          6 |          2 | 24 - 250 ml bottles |   15.5000 |           39 |            0 |            5 |              |
....
+-----------+---------------------------------+------------+------------+---------------------+-----------+--------------+--------------+--------------+--------------+

Sample Output:

Count(ProductName)
69
8

MySQL Online Editor:

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