How to do a case sensitive GROUP BY?

问题

If I execute the code below:

with temp as
(
  select 'Test' as name
  UNION ALL
  select 'TEST'
  UNION ALL
  select 'test'
  UNION ALL
  select 'tester'
  UNION ALL
  select 'tester'
)
SELECT name, COUNT(name)
FROM temp
group by name

It returns the results:

TEST   3
tester 2

Is there a way to have the group by be case sensitive so that the results would be:

Test   1
TEST   1
test   1
tester 2

回答1:

You can use an case sensitive collation:

with temp as
(
  select 'Test' COLLATE Latin1_General_CS_AS as name
  UNION ALL
  select 'TEST'
  UNION ALL
  select 'test'
  UNION ALL
  select 'tester'
  UNION ALL
  select 'tester'
)
SELECT name, COUNT(name)
FROM temp
group by name

回答2:

You need to cast the text as binary (or use a case-sensitive collation).

With temp as
(
  select 'Test' as name
  UNION ALL
  select 'TEST'
  UNION ALL
  select 'test'
  UNION ALL
  select 'tester'
  UNION ALL
  select 'tester'
)
Select Name, COUNT(name)
From temp
Group By Name, Cast(name As varbinary(100))

Using a collation:

Select Name Collate SQL_Latin1_General_CP1_CS_AS, COUNT(name)
From temp
Group By Name Collate SQL_Latin1_General_CP1_CS_AS

回答3:

Simply:

SELECT count(*), CAST(lastname as BINARY) AS lastname_cs 
FROM names 
GROUP BY lastname_cs; 

来源：https://stackoverflow.com/questions/10952696/how-to-do-a-case-sensitive-group-by