how to calculate percentage in column Total in sql

Question

RL   SumAmount      RL     SumAmount
Alex    120         Alex    24.00%  
Jonny   122         Jonny   24.40%  
Jack    13          Jack    2.60%   
David   125         David   25.00%  
Mike    120         Mike    24.00%  

Grand Total 500 Grand Total 100.00%

I was trying to calculate percentage in column Total using sql like below screen shot but getting problem

Answer 1

To get the ratio:

select t.*, sumamount/tot.total
from table t cross join
     (select sum(sumamount) as total from table t) tot;

If you want this expressed as the percentage:

select t.*, concat(format(sumamount/tot.total, 2), '%')
from table t cross join
     (select sum(sumamount) as total from table t) tot;