Percentage calculation in t-sql based on two columns

Question

Hi All
I have a source table with 4 columns and data like this..
ID  Cnt   Col1   Col2 
1    22    17      5   
2    20    15      5   
3    12    5       7   
4    10    null    10    
5    25    25      null   
My output should look like this..
ID  Cnt    Col1   Col2  Col1%   Col22%
1    22    17        5      77.27    22.73
2    20    15        5      75.00    25.00
3    12     5         7      41.66    58.34
4    10               10      0          100
5    25    25                100        0
Create Statement:
CREATE TABLE [dbo].[Sample] (
 [ID] Int NOT NULL,
 [Cnt] Int NULL,
 [Col1]  Int NULL,
 [Col2]  Int NULL,
 CONSTRAINT [Sample] PRIMARY KEY CLUSTERED
 [ID] ASC
Insert Statement:
insert into Sample(ID, cnt,Col1, col2) values (1 ,   22  ,  17   ,   5 )  
insert into Sample(ID, cnt,Col1, col2) values (2 ,  20  ,  15    ,  5   )
insert into Sample(ID, cnt,Col1, col2) values (3 ,   12  ,  5    ,   7 )
insert into Sample(ID, cnt,Col1, col2) values (4 ,   10  ,  null ,   10 )
insert into Sample(ID, cnt,Col1, col2) values (5 ,   25 ,   25   ,   null)
Right now I am using below SQL but % fields are not coming correct.
Select (COUNT(CASE WHEN (col1-col2)) < 1) THEN -1  END)  /COUNT(*) * 100) AS Col1%
,(COUNT(CASE WHEN (col1-col2) >=1) THEN  1  END)  /COUNT(*) * 100) AS Col2%
I need SQL to get correct values in col1% and col2%
Thanks,
RH
sql

Answer 1

Is it what you need:
SELECT Id
,cnt
,col1
,col2
,CASE
WHEN Col1 IS NULL
OR Col1 = 0
THEN 0
ELSE CAST((col1 * 100.0) / cnt AS DECIMAL(10, 2))
END AS [Col1%]
,CASE
WHEN Col2 IS NULL
OR Col2 = 0
THEN 0
ELSE CAST((col2 * 100.0) / cnt AS DECIMAL(10, 2))
END AS [Col2%]
FROM Sample
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