I would do a join with two tables and get me back only one record, the one with the closest date to Now. I am not very practical sql, so if anyone can help me to compose the query. Thank you.
below a picture of all the records, I should make it just go back one, that between the two columns has given the greater, the one closest to now as mentioned earlier.
You can follow below query,
SELECT * FROM (SELECT RGS_Id, r.RGS_DateTime, datediff(ss,r.RGS_DateTime,GETDATE()) diff_value from RGS_Registrazione as r JOIN RGA_Allarmi as a on r.RGS_MCC_Numero_Serie_MS = a.RGS_MCC_Numero_Serie_MS GROUP BY RGS_Id, r.RGS_DateTime) T1 ORDER BY diff_value LIMIT 1;
Hope this should help you out.