我有一个VARCHAR(MAX)字段,它以XML格式连接到外部系统.接口抛出以下错误：
mywebsite.com-2015-0202.xml:413005: parser error : xmlParseCharRef: invalid xmlChar value 29
ne and Luke's family in Santa Fe. You know you have a standing invitation,
^
mywebsite.com-2015-0202.xml:455971: parser error : xmlParseCharRef: invalid xmlChar value 25
The apprentice nodded,because frankly,who hadnt? That diseases like chol
^
mywebsite.com.com-2015-0202.xml:456077: parser error : xmlParseCharRef: invalid xmlChar value 28
bon mot; a sentimental love of nature and animals; the proverbial British 
^
mywebsite.com-2015-0202.xml:472073: parser error : xmlParseCharRef: invalid xmlChar value 20
"Andyou want that?"
^
mywebsite.com-2015-0202.xml:492912: parser error : xmlParseCharRef: invalid xmlChar value 25
She couldnt live like this anymore.
我们发现以下字符列表无效：
�         	 
   
                   
我正在尝试清理这些数据,并且我找到了一个sql函数来清理这些字符here.但是,该函数将NVARCHAR(4000)作为输入参数,因此我将函数更改为使用VARCHAR(MAX).
有人可以建议将NVARCHAR(4000)更改为VARCHAR(MAX)会产生错误的结果吗？对不起,我无法在本地测试此界面,所以想要寻求意见/建议.
原始功能：
CREATE FUNCTION fnStripLowAscii (@InputString nvarchar(4000))
RETURNS nvarchar(4000)
AS
BEGIN
IF @InputString IS NOT NULL
BEGIN
DECLARE @Counter int,@TestString nvarchar(40)
SET @TestString = '%[' + NCHAR(0) + NCHAR(1) + NCHAR(2) + NCHAR(3) + NCHAR(4) + NCHAR(5) + NCHAR(6) + NCHAR(7) + NCHAR(8) + NCHAR(11) + NCHAR(12) + NCHAR(14) + NCHAR(15) + NCHAR(16) + NCHAR(17) + NCHAR(18) + NCHAR(19) + NCHAR(20) + NCHAR(21) + NCHAR(22) + NCHAR(23) + NCHAR(24) + NCHAR(25) + NCHAR(26) + NCHAR(27) + NCHAR(28) + NCHAR(29) + NCHAR(30) + NCHAR(31) + ']%'
SELECT @Counter = PATINDEX (@TestString,@InputString COLLATE Latin1_General_BIN)
WHILE @Counter <> 0
BEGIN
SELECT @InputString = STUFF(@InputString,@Counter,1,NCHAR(164))
SELECT @Counter = PATINDEX (@TestString,@InputString COLLATE Latin1_General_BIN)
END
END
RETURN(@InputString)
END
修改版本：
CREATE FUNCTION [dbo].RemoveInvalidXMLCharacters (@InputString VARCHAR(MAX))
RETURNS VARCHAR(MAX)
AS
BEGIN
IF @InputString IS NOT NULL
BEGIN
DECLARE @Counter INT,@TestString NVARCHAR(40)
SET @TestString = '%[' + NCHAR(0) + NCHAR(1) + NCHAR(2) + NCHAR(3) + NCHAR(4) + NCHAR(5) + NCHAR(6) + NCHAR(7) + NCHAR(8) + NCHAR(11) + NCHAR(12) + NCHAR(14) + NCHAR(15) + NCHAR(16) + NCHAR(17) + NCHAR(18) + NCHAR(19) + NCHAR(20) + NCHAR(21) + NCHAR(22) + NCHAR(23) + NCHAR(24) + NCHAR(25) + NCHAR(26) + NCHAR(27) + NCHAR(28) + NCHAR(29) + NCHAR(30) + NCHAR(31) + ']%'
SELECT @Counter = PATINDEX (@TestString,@InputString COLLATE Latin1_General_BIN)
WHILE @Counter <> 0
BEGIN
SELECT @InputString = STUFF(@InputString,' ')
SELECT @Counter = PATINDEX (@TestString,@InputString COLLATE Latin1_General_BIN)
END
END
RETURN(@InputString)
END
解决方法
使用VARBINARY到base64和back的隐式转换有一个技巧：
在这里你的邪恶名单
DECLARE @evilChars VARCHAR(MAX)= CHAR(0x0) + CHAR(0x1) + CHAR(0x2) + CHAR(0x3) + CHAR(0x4) + CHAR(0x5) + CHAR(0x6) + CHAR(0x7) + CHAR(0x8) + CHAR(0x9) + CHAR(0xa) + CHAR(0xb) + CHAR(0xc) + CHAR(0xd) + CHAR(0xe) + CHAR(0xf) + CHAR(0x10) + CHAR(0x11) + CHAR(0x12) + CHAR(0x13) + CHAR(0x14) + CHAR(0x15) + CHAR(0x16) + CHAR(0x17) + CHAR(0x18) + CHAR(0x19) + CHAR(0x1a) + CHAR(0x1b) + CHAR(0x1c) + CHAR(0x1d) + CHAR(0x1e) + CHAR(0x1f) + CHAR(0x7f);
这很有效
DECLARE @XmlAsString NVARCHAR(MAX)=
(
SELECT @evilChars FOR XML PATH('test')
);
SELECT @XmlAsString;
结果(一些是“打印”)
<test>� 
</test>
以下是禁止的
SELECT CAST(@XmlAsString AS XML)
但是您可以使用VARBINARY到base64的隐式转换
DECLARE @base64 NVARCHAR(MAX)=
(
SELECT CAST(@evilChars AS VARBINARY(MAX)) FOR XML PATH('test')
);
SELECT @base64;
结果
<test>AAECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh9/</test>
现在你已经拥有了真正的XML,包括特殊字符！
SELECT CAST(CAST(@base64 AS XML).value('/test[1]','varbinary(max)') AS VARCHAR(MAX)) FOR XML PATH('reconverted')
