SQL: Common Table Expression
Expressing complex queries in SQL language can be really difficult. Dividing the problem into mini-queries is the best strategy to get the desired results quickly without running into errors. Common Table Expressions, also called CTEs, allow the queries of our interest to be defined once to be reused multiple times when needed. Their clean syntax increases the readability of SQL scripts, allows us to debug written code and to create very complex logic to filter and extract data. Through some examples we will discover their potential.
