Fordi i Oracle behandles en NUL-længde varchar som NULL.
I dit eksempel
NVL(NAME, ' ') AS NAME1 will evaluate to either NAME or ' ' - empty string.
NVL(NAME, '') as NAME2 will evaluate to either NAME or a zero length string
Fordi i Oracle behandles en NUL-længde varchar som NULL.
I dit eksempel
NVL(NAME, ' ') AS NAME1 will evaluate to either NAME or ' ' - empty string.
NVL(NAME, '') as NAME2 will evaluate to either NAME or a zero length string