要提取特殊字符，您首先需要将字符串拆分为行，这样您就可以单独查询每行，这可以使用数字表来完成。如果您没有，它们很容易在运行中创建：
WITH N1 AS (SELECT N FROM (VALUES (1),(1),(1),(1),(1),(1),(1),(1),(1),(1)) n (N)),
N2 (N) AS (SELECT 1 FROM N1 AS N1 CROSS JOIN N1 AS N2),
N3 (N) AS (SELECT 1 FROM N2 AS N1 CROSS JOIN N2 AS N2),
Numbers (Number) AS (SELECT ROW_NUMBER() OVER(ORDER BY N) FROM N3)
SELECT Number
FROM Numbers;
这给出了从 1 到 10000 的数字列表。更多关于这个here。
然后您可以使用条件Number < LEN(Email) 将其加入您的数据，以确保您为电子邮件中的每个字符返回一行，然后使用SUBSTRING() 提取位置n 处的字符：
DECLARE @T TABLE (ID INT IDENTITY, Email NVARCHAR(255));
INSERT @T (Email)
VALUES (N'JóhnSnów@gmail.com'), (N'Khãlessi@gmail.com'), ('NedStark@gmail.com');
WITH N1 AS (SELECT N FROM (VALUES (1),(1),(1),(1),(1),(1),(1),(1),(1),(1)) n (N)),
N2 (N) AS (SELECT 1 FROM N1 AS N1 CROSS JOIN N1 AS N2),
N3 (N) AS (SELECT 1 FROM N2 AS N1 CROSS JOIN N2 AS N2),
Numbers (Number) AS (SELECT ROW_NUMBER() OVER(ORDER BY N) FROM N3)
SELECT t.ID,
t.Email,
Character = SUBSTRING(t.Email, n.Number, 1)
FROM @T AS t
INNER JOIN Numbers n
ON n.Number < LEN(t.Email)
ORDER BY t.ID;
这给出了：
ID Email Character
-----------------------------
1 JóhnSnow@gmail.com J
1 JóhnSnow@gmail.com ó
1 JóhnSnow@gmail.com h
1 JóhnSnow@gmail.com n
1 JóhnSnow@gmail.com S
1 JóhnSnow@gmail.com n
1 JóhnSnow@gmail.com ó
1 JóhnSnow@gmail.com w
.....
然后，您可以通过使用排序规则 SQL_Latin1_General_Cp1251_CS_AS 将它们转换为 VARCHAR 来提取特殊字符，并检查原始字符：
DECLARE @T TABLE (ID INT IDENTITY, Email NVARCHAR(255));
INSERT @T (Email)
VALUES (N'JóhnSnów@gmail.com'), (N'Khãlessi@gmail.com'), ('NedStark@gmail.com');
WITH N1 AS (SELECT N FROM (VALUES (1),(1),(1),(1),(1),(1),(1),(1),(1),(1)) n (N)),
N2 (N) AS (SELECT 1 FROM N1 AS N1 CROSS JOIN N1 AS N2),
N3 (N) AS (SELECT 1 FROM N2 AS N1 CROSS JOIN N2 AS N2),
Numbers (Number) AS (SELECT ROW_NUMBER() OVER(ORDER BY N) FROM N3),
AllCharacters as
( SELECT t.ID,
t.Email,
Character = SUBSTRING(t.Email, n.Number, 1),
Position = n.Number
FROM @T AS t
INNER JOIN Numbers n
ON n.Number < LEN(t.Email)
)
SELECT ac.ID, ac.Character, ac.Position
FROM AllCharacters AS ac
WHERE CONVERT(CHAR(1), ac.Character) COLLATE SQL_Latin1_General_Cp1251_CS_AS <> ac.Character
ORDER BY ac.ID;
结果
ID Email Character Position
----------------------------------------------------
1 JóhnSnów@gmail.com ó 2
1 JóhnSnów@gmail.com ó 7
2 Khãlessi@gmail.com ã 3
最后，如果需要，您可以将XML extensions to concatenate 这些字符用于单个列：
DECLARE @T TABLE (ID INT IDENTITY, Email NVARCHAR(255));
INSERT @T (Email)
VALUES (N'JóhnSnów@gmail.com'), (N'Khãlessi@gmail.com'), ('NedStark@gmail.com');
WITH N1 AS (SELECT N FROM (VALUES (1),(1),(1),(1),(1),(1),(1),(1),(1),(1)) n (N)),
N2 (N) AS (SELECT 1 FROM N1 AS N1 CROSS JOIN N1 AS N2),
N3 (N) AS (SELECT 1 FROM N2 AS N1 CROSS JOIN N2 AS N2),
Numbers (Number) AS (SELECT ROW_NUMBER() OVER(ORDER BY N) FROM N3),
AllCharacters as
( SELECT t.ID,
t.Email,
Character = SUBSTRING(t.Email, n.Number, 1),
Position = n.Number
FROM @T AS t
INNER JOIN Numbers n
ON n.Number < LEN(t.Email)
), SpecialCharacters AS
( SELECT ac.ID, ac.Character, ac.Position
FROM AllCharacters AS ac
WHERE CONVERT(CHAR(1), ac.Character) COLLATE SQL_Latin1_General_Cp1251_CS_AS <> ac.Character
)
SELECT t.ID,
t.Email,
SpecialCharacters = ISNULL(STUFF(s.SpecialCharacterList.value('.', 'NVARCHAR(255)'), 1, 2, ''), '')
FROM @T AS T
CROSS APPLY
( SELECT CONCAT(N', ', s.Character, '(', Position, ')')
FROM SpecialCharacters AS s
WHERE s.ID = t.ID
ORDER BY Position
FOR XML PATH(''), TYPE
) s (SpecialCharacterList)
ORDER BY ID;
结果
ID Email SpecialCharacters
------------------------------------------------
1 JóhnSnów@gmail.com ó(2), ó(7)
2 Khãlessi@gmail.com ã(3)
3 NedStark@gmail.com
顺便说一句，将您视为特殊字符的内容存储在表格中可能更适合您的需求，而不是依赖于特定排序规则的代码页，如果您要这样做，您只需要更改这一行：
WHERE CONVERT(CHAR(1), ac.Character) COLLATE SQL_Latin1_General_Cp1251_CS_AS <> ac.Character
为：
WHERE EXISTS (SELECT 1 FROM MySpecialCharacterTable AS sct WHERE sct.Character = ac.Character)