Database

Grouping Data with GROUP BY The GROUP BY clause is a powerful tool in SQL for organizing and summarizing data. As the name suggests, GROUP BY groups rows that share the same values in specified columns into aggregated data. When you apply GROUP BY, the database engine sorts and combines rows into groups based on the column(s)…

When MySQL processes a query that includes a WHERE clause, it typically has to scan the entire table to locate the matching rows. This kind of full table scan is not very efficient. However, by adding an index to the table, the search for matching rows can be significantly accelerated. The primary purpose of an index is to…