特殊字符 - Sql

Question

如何在 Sql 服务器的列中获取特殊字符？

我有电子邮件列表，我必须找到特殊的字符，例如下面的示例

**Email** 
JóhnSnow@gmail.com
Khãlessi@gmail.com

As u see above , there's '~' and '´'as special characters . Might be appear others characters like '..' or other else.

我正在开发 Sql Server 2012，

有人有解决问题的建议吗？

Answer 1

要提取特殊字符，您首先需要将字符串拆分成行，这样您就可以单独查询每一行，这可以使用数字 table 来完成。如果你没有，它们很容易即时创建：

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 1-10000 的数字列表。关于此的更多信息 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:

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;

给出：

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
.....

然后您可以提取特殊字符，方法是使用排序规则 SQL_Latin1_General_Cp1251_CS_AS 将它们转换为 VARCHAR，并检查其是否为原始字符：

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，您可以使用 XML extensions to concatenate 这些字符到单个列中：

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，如果您要这样做，将您视为特殊字符的内容存储在 table 中可能更适合您的需要，而不是依赖于特定排序规则的代码页，您只需要更改此行：

WHERE   CONVERT(CHAR(1), ac.Character) COLLATE SQL_Latin1_General_Cp1251_CS_AS <> ac.Character

对于：

WHERE EXISTS (SELECT 1 FROM MySpecialCharacterTable AS sct WHERE sct.Character = ac.Character)

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