Common Table Expressions or CTE’s for short are used in SQL to simplify complex joins and subqueries, and to provide a means to query hierarchical data such as an organisational chart. This was also introduced in MySQL 8 – Using https://www.db-fiddle.com/. … Read more ›...

This question can reveal a lot about your ability to write SQL queries as different approaches can be used and there will be drill down on pros and cons of each approach. Q1. Given the following SQL, how do you retrieve the latest records by updated date for each user?...

Data Engineers & analysts must know the Window functions as it is a powerful tool to analyse the data. This post compliments “Apache Spark window functions” focus on using SQL on MySQL server covered. You can also apply this on Big Data SQL engines like Hive & … Read more...