Sql 如何进行区分大小写的分组？

如果我执行以下代码：

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

是否有一种方法可以使分组区分大小写，从而得出以下结果：

Test   1
TEST   1
test   1
tester 2

---

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）

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

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

---

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）

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

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

---

您可以使用区分大小写的排序规则：

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

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

---

您可以使用区分大小写的排序规则：

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

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

简单地说：

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

简单地说：

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

---

在MySQL/MariaDB中，如果不想使用排序规则或转换为二进制，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)

---

在MySQL/MariaDB中，如果不想使用排序规则或转换为二进制，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)

---

有理由选择一种方法而不是另一种方法吗？如果您不知道表可能具有哪些值，可以使用第二种方法。对于MySQL，只需将

VARBINARY

替换为

BINARY

，它工作得很好。是否有理由选择一种方法而不是另一种方法？如果您不知道表可能具有哪些值，可以使用第二种方法。对于MySQL，只需将

VARBINARY

替换为

BINARY

，就可以了。