I would like to understand how to set 0 value of the attribute when it is NULL with MAX function. For example:
Name columns:
number - date
Values:
10 - 2012-04-04
11 - 2012-04-04
12 - 2012-04-04
13 - 2012-04-15
14 - 2012-06-21
1 - 2013-07-04
Number is incremental field, but it has set itself 1 when new year has come.
But result of:
SELECT (MAX(number)+1) number WHERE date LIKE "2014%"
is NULL and not 1 because MAX(number) is NULL and not 0
See Question&Answers more detail:
os 与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…