特殊字符-SQL

Question

如何在SqlServer的列中获取特殊字符？

我收到了电子邮件列表，还必须找到特殊的角色，例如下面的波纹管

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

如您在上面看到的，有〜〜和' ´作为特殊字符 。 可能会出现其他字符，例如“ .. ”或其他字符。

我正在使用Sql Server 2012，

有人建议解决吗？

Answer 1

要提取特殊字符，您首先需要将字符串分成几行，以便可以分别查询每个字符，您可以使用数字表进行查询。 如果您没有，则可以很容易地即时创建它们：

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1-10000的数字列表。 更多关于此这里 。

然后，您可以将其加入条件为Number < LEN(Email)以确保为电子邮件中的每个字符返回上一行，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;

这使：

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SQL_Latin1_General_Cp1251_CS_AS将特殊字符转换为VARCHAR并将其检查为原始字符来提取特殊字符：

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扩展将这些字符连接到单个列中：

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，它可能更适合于您在表中存储算作特殊字符的需求，而不是依赖于代码页进行特定的校对，如果您要这样做，则只需要更改以下行即可：

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)