Calculate the total number of products in SQL

To calculate the total number of products in SQL, you can use the following query:

SELECT COUNT(*) AS total_products
FROM products;

This query will count the number of rows in the products table and return the result in a column labeled total_products.

For example, if the products table contains the following data:

product_id | product_name
---------- | ------------
1          | T-shirt
2          | Jeans
3          | Shoes

Then the following SQL query will return the following result:

total_products
-------------
3

You can also use the WHERE clause to filter the data before counting it. For example, the following query will count the number of products in the products table that are priced at $20 or less:

SELECT COUNT(*) AS total_products
FROM products
WHERE price <= 20;

This query will return the following result:

total_products
-------------
2

You can also use the GROUP BY clause to group the data by a certain column before counting it. For example, the following query will count the number of products in the products table, grouped by category:

SELECT category, COUNT(*) AS total_products
FROM products
GROUP BY category;

This query will return the following result:

category | total_products
-------- | --------------
Clothing | 2
Shoes     | 1

Calculate stock in quantity per week in SQL

To calculate stock in quantity per week in SQL, you can use the following query:

SQL

SELECT week, product_id, SUM(quantity) AS total_stock
FROM (
    SELECT DATE_FORMAT(date, '%W') AS week, product_id, quantity
    FROM stock
) AS t
GROUP BY week, product_id
ORDER BY week, product_id;

This query will first group the stock data by week and product ID. Then, it will calculate the total stock for each week and product ID. Finally, it will order the results by week and product ID.

Here is an example of the output of this query:

week | product_id | total_stock
----- | ---------- | -----------
31   | 1          | 10
31   | 2          | 20
31   | 3          | 30
31   | 4          | 40
31   | 5          | 50

This output shows that there are 10 units of product 1 in stock for week 31, 20 units of product 2 in stock for week 31, and so on.

You can also modify this query to filter the data or to calculate the total stock for a specific product or week. For example, the following query will calculate the total stock for product 1 for week 31:

SELECT SUM(quantity) AS total_stock
FROM stock
WHERE week = DATE_FORMAT(date, '%W') AND product_id = 1;

This query will return the following result:

total_stock
-----------
10

• Date: 08 Nov 2023