MariaDB 10.5

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create table tbl(
   ID int,     
   PRICE  decimal (12,8),         
   SYMBOL varchar(20),         
   Dt timestamp);
Insert  tbl(ID, PRICE, SYMBOL,  Dt)
values
(4450,   247.730000000   ,'AAVEBUSD    ', timestamp '2021-06-20 14:51:54'),
(5964,   248.290000000   ,'AAVEBUSD    ', timestamp '2021-06-20 14:53:01'),
(2936,   246.970000000   ,'AAVEBUSD    ', timestamp '2021-06-20 14:50:48'),
(3024,   0.126500000     ,'AAVEDOWNUSDT', timestamp '2021-06-20 14:50:48'),
(6052,   0.125100000     ,'AAVEDOWNUSDT', timestamp '2021-06-20 14:53:01'),
(4538,   0.125400000     ,'AAVEDOWNUSDT', timestamp '2021-06-20 14:51:54'),
(2935,   0.119240000     ,'AAVEETH     ', timestamp '2021-06-20 14:50:48'),
(5963,   0.119460000     ,'AAVEETH     ', timestamp '2021-06-20 14:53:01'),
(4449,   0.119420000     ,'AAVEETH     ', timestamp '2021-06-20 14:51:54');
select ID, PRICE, SYMBOL,  Dt,
     Price - (select PRICE 
     from tbl t2
     where t2.SYMBOL = t.SYMBOL
          and t2.dt <= t.dt - interval '1' minute
     order by t2.dt desc
     limit 1) diff
from (
     select *, 
       row_number() over(partition by SYMBOL order by dt desc) rn
     from tbl
     ) t 
where rn=1             


ID
PRICE
SYMBOL
Dt
diff


5964
248.29000000
AAVEBUSD
2021-06-20 14:53:01
0.56000000

6052
0.12510000
AAVEDOWNUSDT
2021-06-20 14:53:01
-0.00030000

5963
0.11946000
AAVEETH
2021-06-20 14:53:01
0.00004000

ID	PRICE	SYMBOL	Dt	diff
5964	248.29000000	AAVEBUSD	2021-06-20 14:53:01	0.56000000
6052	0.12510000	AAVEDOWNUSDT	2021-06-20 14:53:01	-0.00030000
5963	0.11946000	AAVEETH	2021-06-20 14:53:01	0.00004000