Basics: Most Commonly used Queries.

A few basic SQL queries for the record, that are frequently used to retrieve, analyze, and manipulate data stored in databases.

Here are some commonly used queries (in the context of retail for examples, my usual experience and simplicity ) :

1. Basic Data Retrieval:

• Retrieve basic information from a table.

SELECT * FROM products;
        

2. Filtering Data:

• Retrieve specific data based on certain conditions.

SELECT * FROM orders WHERE order_status = 'Shipped';
        

3. Sorting Data:

• Retrieve data sorted in ascending or descending order.

SELECT * FROM customers ORDER BY last_name ASC;
        

4. Aggregate Functions:

• Perform calculations on data, like calculating total sales.

SELECT SUM(order_total) AS total_sales FROM orders;
        

5. Grouping and Aggregation:

• Group data based on a column and perform aggregate functions.

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

6. Joins:

• Combine data from two or more tables based on related columns.

SELECT orders.order_id, customers.customer_name
FROM orders
INNER JOIN customers ON orders.customer_id = customers.customer_id;
        

7. Subqueries:

• Use a query result as input for another query.

SELECT product_name
FROM products
WHERE category_id IN (SELECT category_id FROM categories WHERE category_name = 'Electronics');
        

8. Filtering with Date and Time:

• Retrieve data based on date and time conditions.

SELECT * FROM orders WHERE order_date >= '2022-01-01' AND order_date < '2022-02-01';
        

9. Updating Records:

• Modify existing data in a table.

UPDATE products SET price = price * 1.1 WHERE category = 'Apparel';
        

10. Inserting Records:

• Add new data to a table.

INSERT INTO customers (customer_name, email) VALUES ('John Doe', 'john@example.com');
        

11. Deleting Records:

• Remove data from a table.

DELETE FROM customers WHERE customer_id = 101;
        

12. Combining Multiple Conditions:

• Use logical operators to combine conditions.

SELECT * FROM products WHERE price > 50 AND stock_quantity > 0;
        

13. Top N Records:

• Retrieve the top N records based on a specific criterion.

SELECT * FROM products ORDER BY sales DESC LIMIT 10;
        

These SQL queries provide a foundation for managing and extracting valuable insights from retail databases. Depending on specific business requirements, these queries can be customized and extended to suit the analytical needs of a retail environment. What are the top queries that you use daily? feel free to discuss/reach out if you have any questions.