replace-null.md

Replace NULLs

Explore this snippet here.

Description

An essential part of cleaning a new data source is deciding how to treat NULL values. The Snowflake function IFNULL can help with replacing NULL values with something else:

with data as (
  select * from (values
    (1,    'one'),
    (null, 'two'),
    (3,    null)
  ) as data (num, str)
)

select
  ifnull(num, -1) num,
  ifnull(str, 'I AM NULL') str
from data

NUM	STR
1	a
-1	b
3	I AM NULL