Common Interview Questions and Answers
Practice the most frequently asked interview questions with expert answers, approach tips, and AI-powered feedback.
55.7K views•2w ago
What is the purpose of the UNIQUE constraint in SQL?
SQL
Easy
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89.6K views•2w ago
Explain foreign keys and how they enforce referential integrity
SQL
Easy
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63.8K views•2w ago
Explain normalization and describe the different normal forms
SQL
Hard
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135.3K views•2w ago
What is a CTE and when would you use it in SQL?
SQL
Medium
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101.6K views•2w ago
What is a cross join and how does it differ from an inner join?
SQL
Easy
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149.4K views•2w ago
Explain the difference between WHERE and HAVING clauses in SQL
SQL
Medium
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110.3K views•2w ago
What is the difference between UNION and UNION ALL in SQL?
SQL
Easy
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108.9K views•2w ago
What is a composite primary key and when should you use it?
SQL
Medium
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73.3K views•2w ago
Explain the purpose of LAG and LEAD functions in SQL
SQL
Medium
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143.9K views•2w ago
How do you perform pattern matching in SQL using wildcards?
SQL
Easy
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