MySQL Replace function throwing error

Question

I am trying to update ^G (Ctrl G) in a table, below is scenario-

CREATE TABLET TEST(COLA INT,DESCRIPTION VARCHAR(20));

I have crtl G in my data for description field, so to replace it with a \,I am running following command-

UPDATE TEST 
SET DESCRIPTION=REPLACE(DESCRIPTION,CHAR(92),CHAR(7)) 
WHERE DESCRIPTION like '%' CHAR(07) '%';

It runs fine,converts the ^G into \ but it gives a warning as well

TRUNCATED INCORRECT INTEGER VALUE '%'

Can somebody please help me understand this warning.