SQL: DB2 MERGE INTO vs. MySQL REPLACE INTO

Hello,

I struggle to get the concept of MERGE INTO into my head. I'm used about the MySQL REPLACE INTO syntax, though.

REPLACE INTO foo VALUES ('val1', 'val2', 'val3');

This is basically an implicit "if" regarding the primary key field in a table:
- If a record with the primary key value already exists, it is updated with the values given in (),
- if there isn't a record with that primary key value, it's a plain insert.

Can I achieve the same with MERGE INTO? If yes, how?

The examples I found on the net are very elaborated and complex. Thus a very easy example would be more helpful.

Thank you!

:wq! PoC