As you set off on your first round of interviews for a data-focused role, it's almost a given that you can expect to run into questions on SQL and Relational Databases. The good news is, you know this stuff pretty well by now! As we saw from the interview questions we practiced with in this section, there are many different things that can be covered. These can be open-ended questions, such as asking you the sorts of open-ended questions you saw in this lab. When faced with these sorts of interview questions, have an opinion, and be ready to back it up with your rationale! For these sorts of questions, interviewers are often trying to evaluate how you approach problems and evaluate your thought process, so helping them understand your thought process is very important!
You may also expect to run into questions that are meant to check your level of technical aptitude with SQL and Relational Databases. This may come in the form of questions about certain SQL keywords or methodologies, questions on ERD Diagrams, and almost certainly as coding questions asking you to write a SQL query to get some data. Often times when asked to write a query, you'll be given a hypothetical situation and asked to write a query, without having an ERD diagram or tables to look at. When working through these questions, it's important to clarify your assumptions, and to ask questions to make sure that your assumptions are actually correct! Once you have the information you need, be sure to write clean, well-structured SQL code. Consider capitalizing the SQL keywords, and use semantic variable names for any tables or fields you have to assume exist when writing your queries. This is also a situation where thinking out loud and engaging your interviewer is a great strategy. They're likely trying to evaluate how you would work on a team, just as much as they're trying to evaluate your technical knowledge or your ability to get data from a Relational Database.
All of the real-world interview questions you worked through in this section came from popular interview sites such as Glassdoor. If you still feel a bit shaky about your ability answer SQL/Relational Database questions in an interview, that's okay -- practice makes perfect! Don't be afraid to peruse sites like Glassdoor and others to look for the types of SQL questions you can expect to see during the interview process at major companies. Just make sure that when you look at the questions, you try to answer them yourself first before looking at the answers others have posted!