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GROUP BY CASE
WHEN VALUE >= 10 AND VALUE <= 20 THEN '20%'
WHEN VALUE > 20 AND VALUE <= 32.5 THEN '40%' ELSE '0' END
You need to cover all possible values, hence the ELSE 0. You'll probably want to do something a little different there, but it should give you a start.
Based on Joel Gauvreau's comment:
SUM(CASE WHEN VALUE >=10 AND VALUE <= 20 THEN 1.0 ELSE 0.0 END) / COUNT(*),
SUM(CASE WHEN VALUE > 20 AND VALUE <= 32.5 THEN 1.0 ELSE 0.0 END) / COUNT(*)
Or at the end of the query use the COMPUTE statement.
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This will get you the count per range, you can easily determine the percentage from there:
declare @ranges table (beginInclusive float, endExclusive float)
insert @ranges (beginInclusive, endExclusive)
select 10, 20
union all select 20, 32.5
select
r.beginInclusive,
r.endExclusive,
count(*)
from t join @ranges on t.RangedValue >= r.beginInclusive and t.RangedValue < r.endExclusive
group by
r.beginInclusive,
r.endExclusive
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I would usually use a subquery and get rangecounts and join in the total to get the percentage. Something like:
SELECT
RangeCount/CNT as Percentage,
Range
FROM
(
SELECT
Count(*) AS CNT
FROM
SomeTable
) AS Total
LEFT JOIN
(
SELECT
CASE Val <= 10 then
'0 up to 10'
ELSE
CASE when Val <= 20
'11 to 20'
ELSE
'> 20'
END
END
END AS Range,
COUNT(*) AS RangeCount
FROM
SomeTable
GROUP BY
Range
) AS RangeTotals
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SELECT B.Description, Total = COUNT(*) / CONVERT(money, (SELECT COUNT(*) FROM Target T2))
FROM Target T
JOIN (
SELECT Description = '0 to 10', LBound = 0, UBound = 10
UNION ALL
SELECT Description = '10 to 20', LBound = 10, UBound = 20
) B ON T.Value >= LBound AND T.Value < B.UBound
GROUP BY B.Description
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Declare @1 as int
Declare @2 as int
Declare @TotalRows as int
set @1 = (Select COUNT(id) FROM dbo.Table_1 WHERE id >= 10 and id <= 20)
set @2 = (Select COUNT(id) FROM dbo.Table_1 WHERE id > 20 AND id <= 32.5);
set @TotalRows = (Select Count(id) from dbo.Table_1);
SELECT CAST(((@1 * 100)/@TotalRows) as nvarchar(32)) + '%', CAST(((@2 * 100)/@TotalRows) as nvarchar(32)) + '%';
Little complicated, but that does work... i suppose...
dbo.Table_1 only has 1 column, 'id' and it is of type int.
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If it's something that you will be doing regularly, then you can create a table with the ranges and what constitutes those ranges. If not, you can set them up in a table variable or temporary table and join to that. It's basically JohnOpincar's solution, but with a table instead of a subquery.
Also, in your example you list "10 to 20" and "20 to 32.5". Where is a row counted if it's exactly 20? You should probably make sure that your requirements are clear on that point before you deliver the final solution.
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Joel's answer seems the best way to me. Posting to explain the query, and because the answer has an integer division sum/count which will return 1 or 0 instead of a percentage.
For the 20 -> 32.5 range:
select CAST(SUM(
CASE WHEN 20 < field AND field <= 32.5 THEN 1 ELSE 0 END
) as float) / COUNT(*) * 100.0
from table
The case returns 1 when the value is in range. Because there's no group by clause, the sum adds the result of the case for every row in the table. Convert to float, divide by the number of rows =count(*), and you get the percentage.
You can also write it like:
select SUM(
CASE WHEN 20 < field AND field <= 32.5 THEN 1.0 ELSE 0.0 END
) / COUNT(*) * 100
from table
Here the CASE will result in a float 1.0 instead of the integer 1.
