search
Search
Join our weekly DS/ML newsletter layers DS/ML Guides
menu
menu search toc more_vert
Robocat
Guest 0reps
Thanks for the thanks!
close
Comments
Log in or sign up
Cancel
Post
account_circle
Profile
exit_to_app
Sign out
help Ask a question
Share on Twitter
search
keyboard_voice
close
Searching Tips
Search for a recipe:
"Creating a table in MySQL"
Search for an API documentation: "@append"
Search for code: "!dataframe"
Apply a tag filter: "#python"
Useful Shortcuts
/ to open search panel
Esc to close search panel
to navigate between search results
d to clear all current filters
Enter to expand content preview
icon_star
Doc Search
icon_star
Code Search Beta
SORRY NOTHING FOUND!
mic
Start speaking...
Voice search is only supported in Safari and Chrome.
Navigate to
A
A
brightness_medium
share
arrow_backShare
Twitter
Facebook
0
thumb_down
0
chat_bubble_outline
0
auto_stories new
settings

MySQL | WHERE

Database
chevron_right
MySQL
chevron_right
Documentation
chevron_right
Statements and Clauses
schedule Jul 1, 2022
Last updated
local_offer MySQL
Tags
tocTable of Contents
expand_more

The WHERE clause allows us to add conditions to our query. Only records that meet our condition will be retrieved.

MySQL supports the following conditions:

Condition

= (equal)

<> (not equal)

<

>

<=

>=

BETWEEN

LIKE

IN

NOTE

The formal SQL standard defines = and <> as the operators for equal and not equal. Therefore it is not recommended to use == to represent equality, and != to represent inequality.

Syntax

SELECT column_name(s)
FROM table_name
WHERE condition;

Examples

Consider the following table about students' extracurricular activities:

student_id

club

date_entered

1

Football

2016-02-13

2

Boxing

2016-05-25

3

Apple

2018-08-17

4

Fishing

2017-01-01

5

NULL

NULL

The above sample table can be created using the code here.

Basic usage

To retrieve students who were part of a club before 2017-01-01:

SELECT *
FROM extracurricular
WHERE date_entered < '2017-01-01';
+------------+----------+--------------+
| student_id | club | date_entered |
+------------+----------+--------------+
| 1 | Football | 2016-02-13 |
| 2 | Boxing | 2016-05-25 |
+------------+----------+--------------+

Only students with id 1 and 2 were part of a club before 1 January 2017.

To retrieve students who are part of the Fishing club:

SELECT *
FROM extracurricular
WHERE club = 'Fishing';
+------------+---------+--------------+
| student_id | club | date_entered |
+------------+---------+--------------+
| 4 | Fishing | 2017-01-01 |
+------------+---------+--------------+

Filter missing values

We can use the IS NOT NULL operator to filter out NULL records:

SELECT *
FROM extracurricular
WHERE club IS NOT NULL;
+------------+----------+--------------+
| student_id | club | date_entered |
+------------+----------+--------------+
| 1 | Football | 2016-02-13 |
| 2 | Boxing | 2016-05-25 |
| 3 | Chess | 2018-08-17 |
| 4 | Fishing | 2017-01-01 |
+------------+----------+--------------+

We can see the record for student_id=5 has been filtered out.

mail
Join our newsletter for updates on new DS/ML comprehensive guides (spam-free)
robocat
Published by Arthur Yanagisawa
Edited by 0 others
Did you find this page useful?
Ask a question or leave a feedback...
0
thumb_down
0
chat_bubble_outline
0
settings
Enjoy our search
Hit / to insta-search docs and recipes!