Data Analytics and Video Tutorials
A subquery is an SQL select statement that is nested within another SQL statement. As a result data from the subquery can be used in the main query.
Query optimization in SQL refers to the process of improving the performance of SQL queries by selecting the most efficient execution plan for the query. When a SQL query is executed, the database management system (DBMS) must determine the best way to retrieve the requested data from the database. Query optimization involves analyzing the query…
In SQL a lot of the times there will be a need to write subqueries that will extract data that you can analyse. But what if you want to use the data as input to another query that can then be used to give you the result you desire? This is is the power of…