SQL Server 2019 came out in preview a while ago, and the new features announced are just wonderful! A one-to-go-tool for all your big data needs: Unstructured and Structured data that can be processed using just one tool! But the most wonderful feature of all in my opinion are the...
Introduction Recursion in SQL is a lesser known technique, this technique is just like we expect as it would work in any developing language such as C, Javascript, …, it allows us to create a query that will be able to recursively get and process data to find a result. Think...
CTE's (Common Table Expressions) are mostly used when creating recursive queries, creating temporary views (instead of subqueries). Calculating the dates of easter Use case And Example: We want to calculate the dates of when it is easter for the next hundred years. Solution:Since we are explaining examples in SQL...
When creating JOIN queries in SQL we have to realize that we are going to combine every result from the result set with the result set itself. This means that we are going to create a new result set that is the size of the power of 2 of our...
Analytical Functions Analytical functions are brought into existence to solve the problems that we have with Aggregate functions. The biggest disadvantage of these Aggregate functions is that they always reduce the number of results, but what if we want to be able to perform functions on all our results based...
Aggregate Functions Aggregate functions are functions that are going to aggregate data from columns, or rows. Some of these functions are: SUM, AVG, MAX, MIN, …. . Special GROUP BY where we are going to group by values using a CASE and then sort by based on that case Example: In this...
While I was studying the course Databases at the University of Ghent, we encountered some special queries that we were not being thaught in the Professional Bachelor course. This is why I tried to summarise those queries here for everyone to learn from. The database engine being used is Oracle...