multi-row multi-value update in a MySQL transaction

I am using innodb tables in MySQL. I want to update several rows in a table, with each row getting a different value, e.g.:

UPDATE tbl_1 SET
   col1=3  WHERE id=25,
   col1=5  WHERE id=26

In Postgres I believe this is possible:

UPDATE tbl_1 SET col1 = t.col1 FROM (VALUES
        (25, 3)
        (26, 5)
) AS t(id, col1)
WHERE tbl_1.id = t.id;

How do you do this efficiently and effectively in a transaction?

Issues I hit so far:

• using an intermediate temporary MEMORY table turns out to not be transaction safe
• using a TEMPORARY table - persumably MEMORY type again - is virtually undocumented and I can find no re开发者_高级运维al explanation of how it works and how well it works in my case, for example any discussion on whether the table is truncated after each transaction on the session
• using an InnoDB table as a temporary table and filling, joining to update and then truncating it in the transaction seems a very expensive thing to do; I've been fighting MySQL's poor throughput enough as it is

Do you update with a case and set value for col1 depending on id

UPDATE tbl_1 SET col1=CASE id WHEN 25 THEN 3 WHEN 26 THEN 5 END WHERE id IN (25,26)