How to select rows from MySQL table where certain field is empty is a problem i stuggled against for a while like … 10 minutes or so, while solution is quite simple. Remember that it will work with MySQL this solution was not tested with other databases and as far as i am concerned it does not work with Sybase.
SELECT * FROM `table` WHERE `field1` IS NULL
There is also variations for this:
SELECT * FROM `table` WHERE ISNULL(`field1`)
While browsing MySQL documentation i found one more interesting function IFNULL(expr1, expr2). What it basically do is: if expr1 is NULL then it returns expr2 else it returns expr1. Here is a sample usage:
mysql> SELECT IFNULL(1,0); -> 1 mysql> SELECT IFNULL(NULL,10); -> 10 mysql> SELECT IFNULL(1/0,10); -> 10 mysql> SELECT IFNULL(1/0,'yes'); -> 'yes'
That’s it for now, i hope you will find it helpful.
4 Comments on "MySQL Select NULL"
very useful, thank you so much
MySQL people: So, what’s wrong with a good ol’ equals sign – you know, the little double-line thing we use for every other is-equal-to comparison we want to make in MySQL? If I can’t have an explanation of a damned good reason, can I have the last ten minutes of my life back please? and my serenity?
very good and usefull article .Learning alot
Thank you so much, I fuck with it around 1 hour