Mysql using NOT IN gives empty result. Maybe because of NULL values?

Question

Hi I am having the following query:

SELECT *
FROM `workshopmails`
WHERE `workshopmails_mail` NOT
IN (

SELECT workshopklanten_email
FROM `workshopklanten`
)
GROUP BY workshopmails_mail
ORDER BY `workshopmails`.`workshopmails_datum` DESC

But although i know this should give a lot of results it gives the message:

MySQL returned an empty result set (0 rows).

I tried it with an older database and got 100+ results now with my newer data it wont work any more the only thing i can think of is because there are some NULL values in it, that where not in the older database

Does anyone know a solution so i can extract the emails?

Thx Matthy

`NOT IN (SELECT workshopklanten_email FROM workshopklanten WHERE workshopklanten_email IS NOT NULL)` would be one way. — Martin Smith, Mar 24 '13 at 15:21
Your awesome! thanks any reason why null values causes this problem? — matthy, Mar 24 '13 at 15:25
[Explained here](http://stackoverflow.com/questions/5231712/sql-not-in-not-working/5231731#5231731) — Martin Smith, Mar 24 '13 at 15:26

score 0 · Answer 1 · edited May 23 '17 at 12:28

0

Thanks to Martin Smith

NOT IN (SELECT workshopklanten_email FROM workshopklanten WHERE workshopklanten_email IS NOT NULL)

would be one way.

SQL NOT IN not working

edited May 23 '17 at 12:28

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answered Mar 24 '13 at 15:29

matthy

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Mysql using NOT IN gives empty result. Maybe because of NULL values?

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