Joins and Window Functions in SQL

SQL (Structured Query Language) is essential for working with relational databases. Two powerful tools in SQL are Joins and Window Functions . They allow us to combine data from multiple tables and perform complex calculations efficiently. JOINS Joins are the foundation of multi table query processing in SQL. It is a clause used to combine rows from two or more tables. Joins allow us to work with multiple tables and allows us to join data from different tables. We need to have a primary key and a foreign key for us to use joins. Primary and foreign keys allows us to reference from our tables uniquely. Types of Joins EMPLOYEE TABLE DEPARTMENT TABLE We are going to use the above tables to understand joins. 1. INNER JOIN Returns only the rows that match or matching values in both tables. If you want to find the rows with matching values on both the tables you do an Inner Join using the SQL query below; Result of the query; 2. LEFT JOIN Returns all the rows from the left table and the matc