You can use SQL to manipulate all kinds of data, from huge analytical queries to brief single-purpose statements. But you can also use SQL just for fun, without any business requirements stifling your creativity. So, get out your jolly hat and prepare to sing O Christmas Tree as we create some quirky art with plain old SQL. Today, we’re going to generate some holiday-themed ASCII art, just for fun. That’s right.
Hey SQL users! Are you repeating the same query in every report? Are your queries getting too complicated? Organize them with recursive queries! Too many SQL reports can lead to clutter on your desktop and in your head. And is it really necessary to code each of them separately? Ad-hoc queries can share much of the same SQL code with managerial reports and even regulatory reports. Suppose you’ve been writing basic SQL queries for a while.
Common table expressions (CTEs) allow you to structure and organize your SQL code. Being able to write organized queries is a necessity when you begin to move deeper into SQL, so if you want to become an SQL master, you need to know CTEs. The CTE has been part of standard SQL for some time now. CTEs – which are also called WITH statements – are available in all major RDBMS.
Recursive Common Table Expressions are immensely useful when you’re querying hierarchical data. Let’s explore what makes them work. Common Table Expressions (CTEs) are some of the most useful constructions in SQL. Their main purpose is improving query design, which makes queries easier to read. One of the reasons CTEs are so popular is that they let you divide longer queries into shorter subqueries. These are easier to read and edit.