Find the latest staff salary and the last staff salary changes

There is such a demand to find the latest salary situation and the second latest salary situation of personnel, and then calculate an increase situation

The database used is mysql database

The form used is as follows:

Personnel list:listuser

Payroll:ry

sql display

Query the latest data according to time

SELECT a.id,a.dy_id,a.gz,max(a.time) from ry a GROUP BY dy_id

Query the second latest data according to time

SELECT a.id,a.dy_id,a.gz,a.time from ry a where a.id=( SELECT id from ry where a.dy_id=dy_id ORDER BY time LIMIT 1,1 )

Then you can perform a related query