Hello folks, if you are preparing for technical interviews for software developer, system admin, data analyst, or data scientist, one skill you must prepare is SQL. It's one of the important topic for programmers, support engineers and DBAs as you have to deal with SQL in your day to day job. If you don't know, SQL is the declarative language that allows you to interact with the database. By using SQL you can insert, update, search, and delete data in a relational database. The code you write is called SQL queries and it's one of the essential skills for many technical people who have to deal with databases. That's why SQL queries are very popular in interviews and you will often see one or more SQL queries on interviews.