Understanding the Difference Between WHERE and HAVING in SQL

Name: Having vs Where in MySQL | Beginner MySQL Series
Uploaded: 2026-01-13T20:47:00.332109+00:00
Channel: Alex The Analyst
Description: Summary and key takeaways on Understanding the Difference Between WHERE and HAVING in SQL, covering Introduction In this lesson we explore why the `WHERE`

Alex The Analyst

Jan 13, 2026

•

2 min read

YouTube video ID: dCNjUOc1cBY

Source: YouTube video by Alex The Analyst — Watch original video

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Introduction

In this lesson we explore why the WHERE clause cannot be used to filter results based on aggregate functions and how the HAVING clause solves this problem.

Why `WHERE` Fails with Aggregates

WHERE is evaluated before the GROUP BY operation.
When you try to filter on a column that is the result of an aggregate (e.g., AVG(age)), that column does not exist yet because the rows have not been grouped.
Attempting to use WHERE AVG(age) > 40 therefore triggers the error "invalid use of the group by function".

Introducing `HAVING`

HAVING is evaluated after GROUP BY has created the grouped rows.
It is designed specifically for filtering on aggregate results.
Syntax change: replace WHERE with HAVING when the condition involves an aggregate.

Example 1: Demographics Table

Query intent: show genders where the average age is greater than 40.
Original (incorrect) query used WHERE AVG(age) > 40 → error.
Corrected query: sql SELECT gender, AVG(age) AS avg_age FROM demographics GROUP BY gender HAVING AVG(age) > 40;
Result: only the gender(s) whose average age exceeds 40 (in the example, males).

Example 2: Salary Table – Combining `WHERE` and `HAVING`

Table contains occupation and salary columns; two rows for Office Manager with salaries 50,000 and 60,000.
Goal: find managers whose average salary is above 75,000.
Steps:
Row‑level filter with WHERE to keep only occupations that contain the word "manager": sql WHERE occupation LIKE '%manager%'
Group by occupation.
Aggregate filter with HAVING on the average salary: sql HAVING AVG(salary) > 75000
Full query: sql SELECT occupation, AVG(salary) AS avg_salary FROM salary WHERE occupation LIKE '%manager%' GROUP BY occupation HAVING AVG(salary) > 75000;
Outcome: rows that satisfy both the row‑level condition (manager) and the aggregate condition (average salary > 75k).

Key Differences Recap

WHERE
Filters rows before grouping.
Cannot reference aggregate functions.
HAVING
Filters groups after aggregation.
Used exclusively for conditions on aggregate results.
In practice, WHERE is used far more often; HAVING is reserved for aggregate‑based filtering.

What’s Next?

The next lesson will cover the final beginner topics: LIMIT for restricting result sets and aliasing for clearer column names.

Use WHERE to filter raw rows and HAVING to filter aggregated groups; remembering this order eliminates errors when working with aggregate functions.

Frequently Asked Questions

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Yes, the full transcript for this video is available on this page. Click 'Show transcript' in the sidebar to read it.

Why `WHERE` Fails with Aggregates

- `WHERE` is evaluated **before** the `GROUP BY` operation. - When you try to filter on a column that is the result of an aggregate (e.g., `AVG(age)`), that column does not exist yet because the rows have not been grouped. - Attempting to use `WHERE AVG(age) > 40` therefore triggers the error *"invalid use of the group by function"*.

What’s Next?

The next lesson will cover the final beginner topics: `LIMIT` for restricting result sets and aliasing for clearer column names. Use `WHERE` to filter raw rows and `HAVING` to filter aggregated groups; remembering this order eliminates errors when working with aggregate functions.

Summarize another video

Full Transcript YouTube

hello everybody in this lesson we're
going to take a look at the difference
between having and where now in the last
lesson we looked at group by and order
by the most obvious thing to do would be
to come right here and say where and
we're going to say this column which is
actually named this we'll say where the
average age let's say is greater than 40
which would only be the males so let's
go ahead and run this
and as you can see we're not getting any
output let's bring this up and take a
look at the error it says invalid use of
the group by function
what's actually happening is something
to do with this group by gender right
here when we're selecting gender and
then we're performing an aggregate
function this occurs only after the
group by actually groups those rows
together so when we're trying to filter
based off of this column right here of
average age it really hasn't been
created yet because this group by hasn't
happened that's where the having Clause
comes into play so let's go ahead and
what we're going to do is we're going to
get rid of this
we're going to come right down here and
instead of where we're going to say
having
now having was specifically created for
this exact example it comes right after
Group by and after Group by we can
filter based off of these aggregate
functions so now if we run this
we're going to get an output that only
has where the average age is greater
than 40. now let's take a look at just
one more example and I'm going to show
you how you can use both in one query so
instead of demographics let's look at
the salary table
and let's run it
now in this salary table we have this
occupation and remember we have this
office manager that happens twice and
this is going to be our main example so
we're going to say occupation and then
we'll say the average salary
now we'll need to come down here and
we'll say Group by now we're going to
say occupation
so this should look pretty similar
because right here we have our office
manager and one of the office managers
made 50 one of the office managers made
60 so the average is 55 000. now I can
use the where by saying where then I'll
say occupation like and let's see people
who are managers so I'll say a percent
manager percent and close that quote so
they're like a manager
and then I want to see where a manager
makes more than let's say 75 000. so I
won't actually say where I'm going to
say having an average salary
in a out of space there having an
average salary
greater than let's say 75
000.
and let's run this
so now I filtered at the row level right
here in the where Clause but then down
here I filtered out the aggregate
function level this having is only going
to work for aggregated functions after
the group I actually runs so that is the
difference between the having clause and
the where Clause the where Clause you're
most likely going to use a lot more but
if you do want to filter on those
aggregated function columns you have to
use the having Clause I hope that that
was really helpful and in the next
lesson we're looking at our very last
lesson in our beginner series we're
going to look at limit and aliasing
foreign
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