Free practice test
SQL Interview Mock 1
Mock 1 of the SQL Interview Test Series: 15 questions on SQL querying fundamentals in SQL Server (T-SQL): LEFT JOIN results and NULLs, = NULL vs IS NULL, WHERE vs HAVING, COUNT(*) vs COUNT(column), PRIMARY KEY vs UNIQUE, clustered vs nonclustered indexes, UNION vs UNION ALL, NOT IN with NULLs, filtering on ROW_NUMBER, the second-highest salary, nonrepeatable reads, what can go in FROM, OFFSET/FETCH paging, sargable date filters, and ON vs WHERE in outer joins. Mixed formats (query output, find-the-bug, pick-the-query, theory, multi-select and numeric), each with a full teaching explanation after you submit.
- Answers save as you go. Move between questions freely, and mark any to come back to.
- The clock starts when you begin, and the test submits itself at 00:00.
- Keyboard: press A–D to choose an option; ← and → move between questions.
- Questions
- 15
- Time
- 20 min
- Right answer
- +1
- Wrong answer
- 0
15 marks in all · pass mark 9
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