Question

我们最近从SQL Server 2012迁移到SQL Server 2014，所有FOR XML代码都开始抛出有关不可打印ASCII字符的错误。我写了这个可怕的函数来删除不可打印的ASCII字符作为快速修复。我想用更干净的东西代替它。有没有办法做到这一点？

ALTER FUNCTION [dbo].[remove_non_printable_chars]
(@input_string nvarchar(max))
RETURNS nvarchar(max)
BEGIN
    RETURN
    REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(
    REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(
    REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(
    REPLACE(REPLACE(@input_string,
        CHAR(1), ''),CHAR(2), ''),CHAR(3), ''),CHAR(4), ''),CHAR(5), ''),CHAR(6), ''),CHAR(7), ''),CHAR(8), ''),CHAR(9), ''),CHAR(10), ''),
        CHAR(11), ''),CHAR(12), ''),CHAR(13), ''),CHAR(14), ''),CHAR(15), ''),CHAR(16), ''),CHAR(17), ''),CHAR(18), ''),CHAR(19), ''),CHAR(20), ''),
        CHAR(21), ''),CHAR(22), ''),CHAR(23), ''),CHAR(24), ''),CHAR(25), ''),CHAR(26), ''),CHAR(27), ''),CHAR(28), ''),CHAR(29), ''),CHAR(30), ''),
        CHAR(31), ''), NCHAR(0) COLLATE Latin1_General_100_BIN2, '')
END

这是破坏的FOR XML代码。（我没有写这个。它已经在代码库中了。）

SELECT @HTMLTableData =
(
    SELECT  HTMLRows 
    FROM (
        SELECT N'<tr>' + HTMLRow + N'</tr>' AS HTMLRows 
        FROM @HTMLRowData
    ) mi            
    FOR XML PATH(''), TYPE
).value('/', 'NVARCHAR(MAX)')

Answer 1

在线版本：

create function [dbo].[remove_non_printable_chars] (@input_string nvarchar(max))
returns table with schemabinding as return (
  select 
    replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(
    replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(
    replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(
    replace(replace(@input_string collate latin1_general_100_bin2,
        char(1), ''),char(2), ''),char(3), ''),char(4), ''),char(5), ''),char(6), ''),char(7), ''),char(8), ''),char(9), ''),char(10), ''),
        char(11), ''),char(12), ''),char(13), ''),char(14), ''),char(15), ''),char(16), ''),char(17), ''),char(18), ''),char(19), ''),char(20), ''),
        char(21), ''),char(22), ''),char(23), ''),char(24), ''),char(25), ''),char(26), ''),char(27), ''),char(28), ''),char(29), ''),char(30), ''),
        char(31), ''), char(0) , '') 
     as clean_string
);
go

并像这样使用它：

select c.clean_string
from dbo.remove_non_printable_chars(@dirtystring) c

或

select ...
  , c.clean_string
from t
  cross apply dbo.remove_non_printable_chars(t.dirty_string) c

参考：

Answer 2

另一种选择。

此功能将替换控制字符并更正任何残留的重复空格。例如，Jane Smith{13}was here不会返回Jane Smithwas here，而是Jane Smith was here

CREATE FUNCTION [dbo].[udf-Str-Strip-Control](@S varchar(max))
Returns varchar(max)
Begin
    ;with  cte1(N) As (Select 1 From (Values(1),(1),(1),(1),(1),(1),(1),(1),(1),(1)) N(N)),
           cte2(C) As (Select Top (32) Char(Row_Number() over (Order By (Select NULL))-1) From cte1 a,cte1 b)
    Select @S = Replace(@S,C,' ')
     From  cte2

    Return ltrim(rtrim(replace(replace(replace(@S,' ','†‡'),'‡†',''),'†‡',' ')))
End
--Select [dbo].[udf-Str-Strip-Control]('Michael        '+char(13)+char(10)+'LastName')  --Returns: Michael LastName

Answer 3

结合使用REPLACE，PATINDEX和正则表达式，您可以实现所要查询的内容

为了显示一个有效的示例，让我们创建一个表来存储带有不可打印的ASCII字符的字符串

CREATE TABLE ##NoPrintableStrings
(
BadStrings VARCHAR(20)
)

GO

将一些具有不可打印ASCII字符的字符串插入到创建的表中

INSERT ##NoPrintableStrings SELECT ‘The quick ‘ + CHAR(10) + ‘ “brown’
INSERT ##NoPrintableStrings SELECT ‘fox jumped ‘ + CHAR(11) + ‘ ‘
INSERT ##NoPrintableStrings SELECT CHAR(12) + ‘ over the ‘
INSERT ##NoPrintableStrings SELECT ‘ log ‘ + CHAR(13)
INSERT ##NoPrintableStrings SELECT ‘O”Keefe’
— Show the data in the table
SELECT badstrings FROM ##NoPrintableStrings

使用PATINDEX函数的通配符功能更新表以删除所有非字母数字字符

UPDATE  ##NoPrintableStrings
SET badstrings = REPLACE(badstrings, SUBSTRING(badstrings, PATINDEX(‘%[^a-zA-Z0-9 ”””]%’, badstrings), 1), ”)
WHERE PATINDEX(‘%[^a-zA-Z0-9 ”””]%’, badstrings) <> 0

-显示非字母数字字符已被删除

SELECT badstrings FROM ##NoPrintableStrings

来自-https://www.wardyit.com/blog/remove-non-printable-characters-from-a-string/

Answer 4

只需扩展先前的答案

在白名单字符下方，所有其他字符将被清除

[ !`"#$%&'()\*+,\-\./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ\[\]^``\\_abcdefghijklmnopqrstuvwxyz{|}~µº°¡¢£¤¥¦§¨©ª«¬®¯±²³´¶·¸¹»¼½¾¿×÷ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõöøùúûüýþÿ]

我知道它很丑，但是可以。

CREATE FUNCTION [dbo].REPLACE_UNPRINT_CHARS(@VarString nvarchar(256))  
RETURNS nvarchar(256) 
AS    
BEGIN  
    RETURN REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(@VarString, CHAR(0), ''), CHAR(1), ''), CHAR(2), ''), CHAR(3), ''), CHAR(4), ''), CHAR(5), ''), CHAR(6), ''), CHAR(7), ''), CHAR(8), ''), CHAR(9), ''), CHAR(10), ''), CHAR(11), ''), CHAR(12), ''), CHAR(13), ''), CHAR(14), ''), CHAR(15), ''), CHAR(16), ''), CHAR(17), ''), CHAR(18), ''), CHAR(19), ''), CHAR(20), ''), CHAR(21), ''), CHAR(22), ''), CHAR(23), ''), CHAR(24), ''), CHAR(25), ''), CHAR(26), ''), CHAR(27), ''), CHAR(28), ''), CHAR(29), ''), CHAR(30), ''), CHAR(31), ''), CHAR(127), ''), CHAR(128), ''), CHAR(129), ''), CHAR(130), ''), CHAR(131), ''), CHAR(132), ''), CHAR(133), ''), CHAR(134), ''), CHAR(135), ''), CHAR(136), ''), CHAR(137), ''), CHAR(138), ''), CHAR(139), ''), CHAR(140), ''), CHAR(141), ''), CHAR(142), ''), CHAR(143), ''), CHAR(144), ''), CHAR(145), ''), CHAR(146), ''), CHAR(147), ''), CHAR(148), ''), CHAR(149), ''), CHAR(150), ''), CHAR(151), ''), CHAR(152), ''), CHAR(153), ''), CHAR(154), ''), CHAR(155), ''), CHAR(156), ''), CHAR(157), ''), CHAR(158), ''), CHAR(159), ''), CHAR(160), ''); 
END;

用于数据清理

UPDATE [dnName].[dbo].[tableName] 
SET FieldDirtyData= dbo.REPLACE_UNPRINT_CHARS(FieldDirtyData)
WHERE PATINDEX('%['+CHAR(1)+CHAR(2)+CHAR(3)+CHAR(4)+CHAR(5)+CHAR(6)+CHAR(7)+CHAR(8)+CHAR(9)+CHAR(10)+CHAR(11)+CHAR(12)+
CHAR(13)+CHAR(14)+CHAR(15)+CHAR(16)+CHAR(17)+CHAR(18)+CHAR(19)+CHAR(20)+
CHAR(21)+CHAR(22)+CHAR(23)+CHAR(24)+CHAR(25)+CHAR(26)+CHAR(27)+CHAR(28)+CHAR(29)+CHAR(30)+CHAR(31)+CHAR(127)+
CHAR(128)+CHAR(129)+CHAR(130)+CHAR(131)+CHAR(132)+CHAR(133)+CHAR(134)+CHAR(135)+CHAR(136)+CHAR(137)+CHAR(138)+
CHAR(139)+CHAR(140)+CHAR(141)+CHAR(142)+CHAR(143)+CHAR(144)+CHAR(145)+CHAR(146)+CHAR(147)+CHAR(148)+CHAR(149)+CHAR(150)+
CHAR(151)+CHAR(152)+CHAR(153)+CHAR(154)+CHAR(155)+CHAR(156)+CHAR(157)+CHAR(158)+CHAR(159)+CHAR(160)+']%', FieldDirtyData) <> 0

根据需要调整数据类型（nvarchar或varchar + max）

如果要添加更多字符以清除，请使用“选择ASCII（'char要在此处删除字符'）” MSSQL命令来获取字符的ASCII码并将其放入替换指令中

例如SELECT ASCII（'¢'）返回162

因此在行的末尾但在“;”之前，在“ RETURN”和“ CHAR（162），''）”之后再添加一个“ REPLACE（”）。签名。

Answer 5

这是针对此问题的上一个内联表值函数答案 (https://stackoverflow.com/a/43148897/2864740) 的类似答案。主要的变化是这首先使用 patindex 保护，并且当只有一小部分行包含需要替换的字符时快得多。

因此对原始标量函数有两个巨大的改进：

使用内联表值函数。这要快得多，因为它允许 SQL Server 直接内联查询计划中的代码。我尽量避免在旨在扩展的查询中使用标量函数，因为普通标量函数可能会极大地降低性能（即使使用架构绑定）。
使用 patindex 进行初始防护检查。这将在没有要替换的控制字符时 SQL 必须检查的字符数从 O(n * num_replace_calls) 更改为 ~O(n)。由于大多数数据数据（在我的例子中）不包含控制字符，这会导致性能的巨大提升。

-- Only accepts VARCHAR(8000) to avoid a conversion to VARCHAR(MAX);
-- use the suitable input type, which might even be NVARCHAR(MAX).
CREATE FUNCTION DropControlCharactersTv(@str VARCHAR(8000))
RETURNS TABLE
WITH SCHEMABINDING
AS
    RETURN SELECT CleanedString = CASE
    -- No-op.
    WHEN @str IS NULL or @str = '' THEN @str
    -- If any of the non-wanted characters are found then go through the string and replace each occurrence of every character.
    -- This guard significantly improves the performance when very few strings need to be corrected.
    WHEN PATINDEX (
        '%[' + CHAR(0) + CHAR(1) + CHAR(2) + CHAR(3) + CHAR(4) + CHAR(5) + CHAR(6) + CHAR(7) + CHAR(8) + CHAR(11) + CHAR(12) + CHAR(14) + CHAR(15) + CHAR(16) + CHAR(17) + CHAR(18) + CHAR(19) + CHAR(20) + CHAR(21) + CHAR(22) + CHAR(23) + CHAR(24) + CHAR(25) + CHAR(26) + CHAR(27) + CHAR(28) + CHAR(29) + CHAR(30) + CHAR(31) + CHAR(127) + ']%',
        @str COLLATE Latin1_General_BIN) <> 0 THEN
        -- Replace, nested.
        -- See https://www.sqlservercentral.com/forums/topic/how-to-remove-characters-char0-to-char31
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        REPLACE(
        @str
        ,CHAR(0),'') COLLATE Latin1_General_BIN
        ,CHAR(1),'') COLLATE Latin1_General_BIN
        ,CHAR(2),'') COLLATE Latin1_General_BIN
        ,CHAR(3),'') COLLATE Latin1_General_BIN
        ,CHAR(4),'') COLLATE Latin1_General_BIN
        ,CHAR(5),'') COLLATE Latin1_General_BIN
        ,CHAR(6),'') COLLATE Latin1_General_BIN
        ,CHAR(7),'') COLLATE Latin1_General_BIN
        ,CHAR(8),'') COLLATE Latin1_General_BIN
        ,CHAR(9),'') COLLATE Latin1_General_BIN
        ,CHAR(10),'') COLLATE Latin1_General_BIN
        ,CHAR(11),'') COLLATE Latin1_General_BIN
        ,CHAR(12),'') COLLATE Latin1_General_BIN
        ,CHAR(13),'') COLLATE Latin1_General_BIN
        ,CHAR(14),'') COLLATE Latin1_General_BIN
        ,CHAR(15),'') COLLATE Latin1_General_BIN
        ,CHAR(16),'') COLLATE Latin1_General_BIN
        ,CHAR(17),'') COLLATE Latin1_General_BIN
        ,CHAR(18),'') COLLATE Latin1_General_BIN
        ,CHAR(19),'') COLLATE Latin1_General_BIN
        ,CHAR(20),'') COLLATE Latin1_General_BIN
        ,CHAR(21),'') COLLATE Latin1_General_BIN
        ,CHAR(22),'') COLLATE Latin1_General_BIN
        ,CHAR(23),'') COLLATE Latin1_General_BIN
        ,CHAR(24),'') COLLATE Latin1_General_BIN
        ,CHAR(25),'') COLLATE Latin1_General_BIN
        ,CHAR(26),'') COLLATE Latin1_General_BIN
        ,CHAR(27),'') COLLATE Latin1_General_BIN
        ,CHAR(28),'') COLLATE Latin1_General_BIN
        ,CHAR(29),'') COLLATE Latin1_General_BIN
        ,CHAR(30),'') COLLATE Latin1_General_BIN
        ,CHAR(31),'') COLLATE Latin1_General_BIN
        ,CHAR(127),'') COLLATE Latin1_General_BIN
    -- Did not match pattern: inherently valid
    ELSE @str END

在查询中：

select
    Plucker.CleanedString
from Goose d
cross apply DropControlCharactersTv(d.Turkey) as Plucker

SQL Server - 删除所有不可打印的ASCII字符

5 个答案: