sql server数据类型转换

Question

I have table with column Percentage varchar(10) Data in that table is

Pecentage
2/10
4/10
6/10
..............

Now I have to convert above percentage to decimal,so now i am doing like this. select CAST(percentage as decimal) from TabName I am getting following exception Error converting data type varchar to numeric.

I would like to get the results like 0.2,0.4,0.6

Answer 1

You cannot convert that varchar format(2/10) to float .You need to get the individual string and then perform the division

Declare @Sample Table
(Percentage varchar(10))

Insert into @Sample
values
('2/10'),('4/10'),('6/10')

;With CTE (Numerator,denominator)
as
(
  Select cast(substring(Percentage,0,charindex('/',percentage))as float),
  cast(substring(Percentage,charindex('/',percentage)+1,len(Percentage)) as float)
  from @Sample
)
select Numerator/denominator from CTE 

Result

(No column name)
0.2
0.4
0.6

Answer 2

Try this

declare @str varchar(20)='2/10'

select @str, CAST(LEFT(@str,CHARINDEX('/',@str)-1) as DECIMAL(10,5))/CAST(RIGHT(@str,LEN(@str)-CHARINDEX('/',@str)) as DECIMAL(10,5))

Answer 3

Declare @Temp Table
(Percentage varchar(10))

Insert into @Temp
values
('2/10'),('4/10'),('6/10')


select 
convert(float,SUBSTRING (Percentage ,0 , charindex('/',Percentage)))/    
convert(float,SUBSTRING (Percentage ,charindex('/',Percentage)+1,len(Percentage))) 
as Result

from @Temp