sql - 如何进行区分大小写的 GROUP BY？

Question

如果我执行下面的代码：

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

它返回结果：

TEST   3
tester 2

有没有办法让 group by 区分大小写，以便结果是：

Test   1
TEST   1
test   1
tester 2

Answer 1

您需要将文本转换为二进制（或使用区分大小写的排序规则）。

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))

使用排序规则：

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

Answer 2

您可以使用区分大小写的排序规则：

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

Answer 3

简单地：

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

Answer 4

在 MySQL/MariaDB 中，如果您不想使用排序规则或强制转换为二进制，只需使用：

SELECT MAX(name), COUNT(name)
FROM (
  select 'Test' as name
  UNION ALL
  select 'TEST'
  UNION ALL
  select 'test'
  UNION ALL
  select 'test'
  UNION ALL
  select 'tester'
  UNION ALL
  select 'tester'
) as tmp
group by MD5(name)