How to solve the UPDATE problem for a float field?

Question

MySQL

There is a request:

UPDATE `teasers_images` SET `status` = 'on' WHERE `ctr` <= '0.4'

which does not update the required values ​​(writes "0 rows affected.").
As far as I understand there is some problem with float (field type ctr is float).
At the same time, SELECT on this query is successfully executed and returns the result.
Tell me how to solve the problem?

Answer 1

Maybe you shouldn't do it as a string? Why quotation marks?