SQL comments are used to explain and annotate code, making it easier for developers and teams to understand. Though comments don’t affect query execution, they play a vital role in documentation and debugging.
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Which operator is used to check for NULL values in SQL?
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Question 3 of 15
3. Question
What is the result of NULL = NULL in SQL?
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Question 4 of 15
4. Question
How do you check if a column is not NULL?
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Question 5 of 15
5. Question
Which of the following statements will return rows where salary is missing?
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Question 6 of 15
6. Question
What does the COALESCE() function do in SQL?
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Question 7 of 15
7. Question
What is the result of this query: SELECT COALESCE(NULL, NULL, ‘SQL’);?
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Question 8 of 15
8. Question
Which function can be used to replace NULL with a custom value?
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Question 9 of 15
9. Question
How does the COUNT() function treat NULLs?
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Question 10 of 15
10. Question
What is returned by: SELECT COUNT(*) FROM employees;
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Question 11 of 15
11. Question
In SQL, which comparison involving NULL returns TRUE?
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Question 12 of 15
12. Question
Which of the following will return 0 if the column contains NULL?
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Question 13 of 15
13. Question
What is the default behavior of GROUP BY when NULLs are present?
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Question 14 of 15
14. Question
What happens when NULL is used in an arithmetic expression?
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Question 15 of 15
15. Question
Which function helps to avoid NULL-related issues in aggregate calculations?
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Summary
This quiz on SQL Comments reinforces best practices for using single-line and multi-line comments effectively in SQL. Ideal for beginners, professionals, and anyone writing maintainable SQL code.
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