SQL QUERIES

SQL (Structured Query Language) is a programming language designed for managing and manipulating data stored in relational database management systems (RDBMS). It is used to perform various operations such as:

• Creating and modifying database structures (tables, indexes, views, etc.)
• Inserting, updating, and deleting data
• Querying data (retrieving specific data or aggregations)
• Managing database security and permissions

SQL is a standard language for accessing, managing, and modifying data in relational databases. It is widely used in various industries and applications, including:

• Database administration
• Web development
• Business intelligence
• Data analysis and science
• Enterprise software applications

COMMON SQL QUERIES COMMAND

1. SELECT: The columns you want to retrieve
2. FROM: The tables you want to retrieve data from
3. WHERE: The conditions that must be met for a row to be included in the results
4. GROUP BY: How you want to group the results (optional)
5. HAVING: Conditions that must be met for a group to be included in the results (optional)
6. ORDER BY: How you want to sort the results (optional)
7. LIMIT: The maximum number of rows you want to retrieve (optional)

Here's a basic example:

SELECT * FROM customers WHERE country='USA' AND age>18 ORDER BY last_name LIMIT 10;

This query:

• Selects all columns (*)
• From the customers table
• Where the country is 'NIGERIA' and the age is greater than 18
• Orders the results by the last_name column
• Limits the results to 10 rows

Note: The specific columns, tables, and conditions will vary depending on your database schema and the data you're trying to retrieve.

Here are some more examples:

• SELECT * FROM orders WHERE total_amount > 100; (Retrieve all orders with a total amount greater than 100)
• SELECT customer_name, order_date FROM orders WHERE order_date > '2024-07-10'; (Retrieve the customer name and order date for all orders placed after July 10, 2024)
• SELECT * FROM products WHERE price < 50 AND category='electronics'; (Retrieve all products with a price less than 50 and a category of 'electronics')