SQL Theory Interview Question for Fresher

SQL Theory Interview Question for Fresher, Dear fresher “Developers” here you going to get actual interview question for “Full Stack Developers”. These all question is give enogh knowleg and overview of SQL Theory Interview Question which help to you in your interview. So lets start.

Difference between Where and Having clause?

1.WHERE clause can be used with – Select, Insert, and Update statements, where as HAVING clause can only be used with the Select statement.

2. WHERE clause filters rows before aggregation (GROUPING), whereas, HAVING clause filters groups, after the aggregations are performed.

3. Aggregate functions cannot be used in the WHERE clause, unless it is in a sub query contained in a HAVING clause, whereas, Aggregate functions can be used in HAVING clause.

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