update int field that is null

[BubikolRamios]

Update table set field= field+1 where id = '74'

Field is type INTEGER
if initial field = null --> no error , no update.

Any comment on that

[bdl]

Take a look at the MySQL page entitled "problems with NULL values".

Basically, any expression with a NULL value ends with a NULL value. In your case, you state that the field is NULL when you start the UPDATE. Adding any value to a NULL is NULL. Thus, the field is technically updating, it's just staying NULL. Make sense?

[Old Pedant]

There is, however, an easy fix:

UPDATE table SET field = IFNULL(field,0) + 1 WHERE id = '74';