What are some advanced SQL commands I should know?

What are some advanced SQL commands I should know?

Some advanced SQL commands include CTEs (Common Table Expressions), window functions, and recursive queries.

Can you explain how to use window functions?

Sure! Window functions allow you to perform calculations across a set of table rows related to the current row. For example, you can use ROW_NUMBER(), RANK(), or SUM() OVER().

What is a CTE and how do I create one?

A CTE, or Common Table Expression, is a temporary result set that you can reference within a SELECT, INSERT, UPDATE, or DELETE statement. You create one using the WITH clause.

Can you give me an example of a recursive CTE?

Certainly! A recursive CTE can be used to generate a series of numbers or to traverse hierarchical data. Here's a simple example:

WITH RECURSIVE numbers AS (
    SELECT 1 AS num
    UNION ALL
    SELECT num + 1 FROM numbers WHERE num < 10
)
SELECT * FROM numbers;