Easy SQL Question 42 of 226

When do you use WHERE versus HAVING?

Java Specialist · Speak this in 60–90 seconds · Faridabad & Delhi NCR

Without indexScan every row

With indexJump to keys

CostWrites slower

WHERE filters rows before grouping.

Why interviewers care about SQL:

They want a clean

contrast on SQL, not two memorised paragraphs.

Say what changes for

the developer, then one case where picking wrong hurts.

Stay structured

Name the idea, why it exists, then one short example.

Close cleanly

End with when you use it and one common pitfall.

Before you speak the answer, walk the interviewer through these steps:

1
Define it
WHERE filters rows before grouping.
2
HAVING filters groups after
GROUP BY, so it can use aggregates like COUNT or SUM.
3
You can still put
non-aggregate predicates in WHERE to reduce rows early, which is usually cheaper.
4
Give an example
One tiny concrete case you can say aloud.
5
Common mistake
What juniors usually get wrong.
6
Close
When you pick this over the alternative.

Here's a short line you can speak, broken into clear beats:

Say this line

“HAVING filters groups after GROUP BY, so it can use aggregates like COUNT or SUM”

Break into beats

HAVINGfiltersgroupsafterGROUPBY

Speaking order

2987408337471632900

Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.

WHERE filters rows before grouping. HAVING filters groups after GROUP BY, so it can use aggregates like COUNT or SUM.