How to use the SQL Interview Flashcards
- 1. Choose topicsPick one topic or all of them, a round size, and whether to skip cards you already know.
- 2. Flip and gradeRead the question, answer aloud, then reveal the answer and mark it known or still learning.
- 3. Review your resultsMissed cards come back later in the round. At the end see your score by topic and download the cards to revise.
What the deck covers
SQL comes up in almost every tech interview, whether the role is analyst, developer or tester, and this deck covers the questions that are asked again and again. The 23 cards are grouped into 10 topics: Basics, Queries, Joins, Aggregates, Window functions, Subqueries, Design, Performance, Transactions, Misc. Answers are short on purpose: one or two sentences you can say out loud, which you then back up with an example from your own projects.
A card from the deck
Q: Find the second highest salary.
A: SELECT MAX(salary) FROM emp WHERE salary < (SELECT MAX(salary) FROM emp); or use DENSE_RANK() and pick rank 2.
Interviewers often follow up by asking for the third or nth highest salary, which is where DENSE_RANK() is cleaner than nested MAX() queries.
How to study with it
- Write each query card on paper or in a SQL editor; syntax slips show up only when you type it.
- Learn the logical order of SELECT; it explains why aliases can't be used in WHERE.
- In the SQL deck, cards you mark "still learning" come back three cards later in the same round, and the results screen lists them so you can download a revision sheet.
More questions from this deck
Other SQL questions you'll meet include:
- Primary key vs unique key?
- What is the logical order a SELECT runs in?
- What is a self join?
- RANK vs DENSE_RANK vs ROW_NUMBER?
- What is normalisation?
Frequently asked questions
Which database do answers follow?
Standard SQL that works in MySQL 8, PostgreSQL and SQL Server, with differences noted.
Do I need to memorise syntax?
Know the common clauses by heart; for rarer functions, knowing they exist is usually enough.
Are the SQL interview flashcards free?
Yes. You can flip through every card of the SQL interview flashcards without signing up. When you open your results for the first time, we ask once for your name and WhatsApp number; after that the SQL interview flashcards and every other Uncodemy tool open straight away.