MySQL + SQL · Lesson 123

MySQL Interview Questions

Common MySQL Interview Questions

Practical MySQL/SQL questions often asked in interviews.

Question	Short Answer
WHERE vs HAVING?	WHERE filters rows; HAVING filters groups.
INNER vs LEFT JOIN?	INNER = matches only; LEFT = all left rows + matches.
What is an index?	A structure that speeds up searches.
What is a view?	A saved query acting as a virtual table.
How to prevent SQL injection?	Use prepared statements.
InnoDB vs MyISAM?	InnoDB has transactions & foreign keys; MyISAM does not.

Question	Short Answer
WHERE बनाम HAVING?	WHERE rows filter; HAVING groups filter।
INNER बनाम LEFT JOIN?	INNER = सिर्फ matches; LEFT = सारी left rows + matches।
Index क्या है?	Searches तेज़ करने वाली structure।
View क्या है?	Virtual table की तरह saved query।
SQL injection कैसे रोकें?	Prepared statements use करें।
InnoDB बनाम MyISAM?	InnoDB में transactions व foreign keys; MyISAM में नहीं।

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