select case when length(message) > 7
then concat(substring(message, 1, 7), '...')
else message end as adapted_message
from ...
för att testa/bekräfta:
SELECT CASE WHEN LENGTH('1234567890') > 7
THEN CONCAT(SUBSTRING('1234567890', 1, 7), '...')
ELSE '1234567890' END AS adapted_message
UNION
SELECT CASE WHEN LENGTH('12345') > 7
THEN CONCAT(SUBSTRING('12345', 1, 7), '...')
ELSE '12345' END AS adapted_message