SQL is a really versatile language, letting you join tables on almost any column using various predicates. Most commonly we join tables on primary and foreign keys with equality. But there are times when you might join on different columns. For instance, imagine you want to link a table of employees with a table of projects based on job roles instead of IDs. In short, you could say: "Find all employees and the projects they are working on where the employee’s job role matches the projects required role." Heres how you would write that in SQL:

SELECT employees.name, projects.project_name

FROM employees

JOIN projects ON employees.job_role = projects.required_role;

I find SQL to be a powerful and fairly intuitive language for working with databases. It’s straightforward for basic tasks but can get tricky with complex queries. Dealing with nested queries and multiple conditions can be challenging and often requires a solid understanding of both the database structure and the logical flow of the query.