Fresher interviews test fundamentals, not tricks. These are the questions that appear again and again in data analyst and developer interviews — prepare crisp answers with examples.
Key Points
- What is a primary key vs foreign key? (Definitions + one example each)
- Explain the JOIN types and when you'd use LEFT vs INNER
- DELETE vs TRUNCATE vs DROP — rollback and speed differences
- WHERE vs HAVING — before vs after grouping
- What are constraints? Name five with use cases
- Write a query: second-highest salary, duplicates in a table, department-wise counts
Pro tip: interviewers value a spoken example ('for instance, customers and orders…') far more than a memorised definition.
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