DECODE( expr
val_1 , result_1 ,
val_2 , result_2 ,
val_3 , result_3 ,
)
expr with val_n and returns result_n for the first val_n that is equal to expr. DECODE( expr
val_1 , result_1 ,
…
default_value
)
decode compares null values differently than one is used to from Oracle in that decode considers null to be equal to null. select
decode( null ,
null, 42,
'xyz', 99,
17)
from
dual;