How to return 0 instead of NULL with MySQL
Just banged my head on this one today while working on a new project in C#.
Here’s how you can return 0 in case SUM() or any other math function returns NULL.
SELECT COALESCE((SUM(myfield)),0) FROM mytable;
COALESCE() returns the first non-null value, therefore if SUM() is null, then it will return the following 0.
