如何仅替换/覆盖雪花表中的某些值？

Question

I have a Snowflake SQL command in the form of:

CREATE TASK REPLACE_CERTAIN_ROWS
WAREHOUSE=<MY_WAREHOUSE>
SCHEDULE='USING CRON 0 5,17 * * * UTC'
AS
insert overwrite into <MY_SCHEMA>.<MY_TABLE>(FIELD1,FIELD2)
<MY_SQL>

And my table looks like:

FIELD1|FIELD2
ABC,REPLACE
DEF,REPLACE
GHI,DONTREPLACE
JKL,DONTREPLACE

Instead of replacing the entire table how can I alter my Snowflake to only overwrite the FIELD2="REPLACE" rows? Do I have to first have a command that deletes these rows or is there a way to do it more instantaneously? I know I can only execute one command per Snowflake task so would like to avoid managing dependent tasks and do it all in the same task/command.

Desired Result:

FIELD1|FIELD2
GHI,DONTREPLACE <- remained
JKL,DONTREPLACE <- remained
MNO,REPLACE <- was replaced
PQR,REPLACE <- was replaced

Answer 1

UPDATE is the normal way to do this:

UPDATE <MYDB>.<MY_SCHEMA>.<MY_TABLE> SET field1 = <new value> WHERE field2 = 'REPLACE';

but if you are trying to drive this from a TABLE/STREAM then MERGE is more what you will want.