ACTUALIZACIÓN si la columna no es nulo, si es nulo, al dejar nula

Question

tengo el siguiente código SQL:

UPDATE TableA 
SET first_name = 'AAA', 
    last_name = 'BBB', 
    address1 = '123', 
    address2 = 'Fake St.,', 
    phone = '1234567', 
    id = '11223344' 

Qué debo usar para actualizar cada columna solamente si no es nulo?

Answer 1

update tableA 
set first_name = case when first_name is null then null else 'aaa' end, 
last_name = case when last_name is null then null else 'bbb' end, 
... 

Answer 2

Sólo otro enfoque menos detallado (y menos legible):

UPDATE TableA 
SET first_name = left( 'AAA' + first_name, 3) , 
    last_name = left( 'BBB' + last_name, 3) , 
    address1 = left( '123' + address1, 3) , 
    address2 = left( 'Fake St.,' + address2, len('Fake St.,')) , 
    ...