我需要对存储 URL 编码文本的旧表运行查询。我需要在我的结果中解码此文本。我如何实现这一目标？
问问题
32131 次
4 回答
29
尝试其中之一：
CREATE FUNCTION dbo.UrlDecode(@url varchar(3072))
RETURNS varchar(3072)
AS
BEGIN
DECLARE @count int, @c char(1), @cenc char(2), @i int, @urlReturn varchar(3072)
SET @count = Len(@url)
SET @i = 1
SET @urlReturn = ''
WHILE (@i <= @count)
BEGIN
SET @c = substring(@url, @i, 1)
IF @c LIKE '[!%]' ESCAPE '!'
BEGIN
SET @cenc = substring(@url, @i + 1, 2)
SET @c = CHAR(CASE WHEN SUBSTRING(@cenc, 1, 1) LIKE '[0-9]'
THEN CAST(SUBSTRING(@cenc, 1, 1) as int)
ELSE CAST(ASCII(UPPER(SUBSTRING(@cenc, 1, 1)))-55 as int)
END * 16 +
CASE WHEN SUBSTRING(@cenc, 2, 1) LIKE '[0-9]'
THEN CAST(SUBSTRING(@cenc, 2, 1) as int)
ELSE CAST(ASCII(UPPER(SUBSTRING(@cenc, 2, 1)))-55 as int)
END)
SET @urlReturn = @urlReturn + @c
SET @i = @i + 2
END
ELSE
BEGIN
SET @urlReturn = @urlReturn + @c
END
SET @i = @i +1
END
RETURN @urlReturn
END
GO
来自http://sqlblog.com/blogs/peter_debetta/archive/2007/03/09/t-sql-urldecode.aspx
CREATE FUNCTION dbo.fnDeURL
(
@URL VARCHAR(8000)
)
RETURNS VARCHAR(8000)
AS
BEGIN
DECLARE @Position INT,
@Base CHAR(16),
@High TINYINT,
@Low TINYINT,
@Pattern CHAR(21)
SELECT @Base = '0123456789abcdef',
@Pattern = '%[%][0-9a-f][0-9a-f]%',
@URL = REPLACE(@URL, '+', ' '),
@Position = PATINDEX(@Pattern, @URL)
WHILE @Position > 0
SELECT @High = CHARINDEX(SUBSTRING(@URL, @Position + 1, 1), @Base COLLATE Latin1_General_CI_AS),
@Low = CHARINDEX(SUBSTRING(@URL, @Position + 2, 1), @Base COLLATE Latin1_General_CI_AS),
@URL = STUFF(@URL, @Position, 3, CHAR(16 * @High + @Low - 17)),
@Position = PATINDEX(@Pattern, @URL)
RETURN @URL
END
于 2010-09-30T17:36:08.993 回答
3
如果您需要支持非英文字符（unicode）的解决方案，CodeProject上有一个很好的示例：
CREATE FUNCTION [dbo].[UrlDecode] (
@URL NVARCHAR(4000) ) RETURNS NVARCHAR(4000) AS BEGIN
DECLARE @Position INT, @Base CHAR(16), @High TINYINT, @Low TINYINT, @Pattern CHAR(21)
DECLARE @Byte1Value INT, @SurrogateHign INT, @SurrogateLow INT
SELECT @Pattern = '%[%][0-9a-f][0-9a-f]%', @Position = PATINDEX(@Pattern, @URL)
WHILE @Position > 0
BEGIN
SELECT @High = ASCII(UPPER(SUBSTRING(@URL, @Position + 1, 1))) - 48,
@Low = ASCII(UPPER(SUBSTRING(@URL, @Position + 2, 1))) - 48,
@High = @High / 17 * 10 + @High % 17,
@Low = @Low / 17 * 10 + @Low % 17,
@Byte1Value = 16 * @High + @Low
IF @Byte1Value < 128 --1-byte UTF-8
SELECT @URL = STUFF(@URL, @Position, 3, NCHAR(@Byte1Value)),
@Position = PATINDEX(@Pattern, @URL)
ELSE IF @Byte1Value >= 192 AND @Byte1Value < 224 AND @Position > 0 --2-byte UTF-8
BEGIN
SELECT @Byte1Value = (@Byte1Value & (POWER(2,5) - 1)) * POWER(2,6),
@URL = STUFF(@URL, @Position, 3, ''),
@Position = PATINDEX(@Pattern, @URL)
IF @Position > 0
SELECT @High = ASCII(UPPER(SUBSTRING(@URL, @Position + 1, 1))) - 48,
@Low = ASCII(UPPER(SUBSTRING(@URL, @Position + 2, 1))) - 48,
@High = @High / 17 * 10 + @High % 17,
@Low = @Low / 17 * 10 + @Low % 17,
@Byte1Value = @Byte1Value + ((16 * @High + @Low) & (POWER(2,6) - 1)),
@URL = STUFF(@URL, @Position, 3, NCHAR(@Byte1Value)),
@Position = PATINDEX(@Pattern, @URL)
END
ELSE IF @Byte1Value >= 224 AND @Byte1Value < 240 AND @Position > 0 --3-byte UTF-8
BEGIN
SELECT @Byte1Value = (@Byte1Value & (POWER(2,4) - 1)) * POWER(2,12),
@URL = STUFF(@URL, @Position, 3, ''),
@Position = PATINDEX(@Pattern, @URL)
IF @Position > 0
SELECT @High = ASCII(UPPER(SUBSTRING(@URL, @Position + 1, 1))) - 48,
@Low = ASCII(UPPER(SUBSTRING(@URL, @Position + 2, 1))) - 48,
@High = @High / 17 * 10 + @High % 17,
@Low = @Low / 17 * 10 + @Low % 17,
@Byte1Value = @Byte1Value + ((16 * @High + @Low) & (POWER(2,6) - 1)) * POWER(2,6),
@URL = STUFF(@URL, @Position, 3, ''),
@Position = PATINDEX(@Pattern, @URL)
IF @Position > 0
SELECT @High = ASCII(UPPER(SUBSTRING(@URL, @Position + 1, 1))) - 48,
@Low = ASCII(UPPER(SUBSTRING(@URL, @Position + 2, 1))) - 48,
@High = @High / 17 * 10 + @High % 17,
@Low = @Low / 17 * 10 + @Low % 17,
@Byte1Value = @Byte1Value + ((16 * @High + @Low) & (POWER(2,6) - 1)),
@URL = STUFF(@URL, @Position, 3, NCHAR(@Byte1Value)),
@Position = PATINDEX(@Pattern, @URL)
END
ELSE IF @Byte1Value >= 240 AND @Position > 0 --4-byte UTF-8
BEGIN
SELECT @Byte1Value = (@Byte1Value & (POWER(2,3) - 1)) * POWER(2,18),
@URL = STUFF(@URL, @Position, 3, ''),
@Position = PATINDEX(@Pattern, @URL)
IF @Position > 0
SELECT @High = ASCII(UPPER(SUBSTRING(@URL, @Position + 1, 1))) - 48,
@Low = ASCII(UPPER(SUBSTRING(@URL, @Position + 2, 1))) - 48,
@High = @High / 17 * 10 + @High % 17,
@Low = @Low / 17 * 10 + @Low % 17,
@Byte1Value = @Byte1Value + ((16 * @High + @Low) & (POWER(2,6) - 1)) * POWER(2,12),
@URL = STUFF(@URL, @Position, 3, ''),
@Position = PATINDEX(@Pattern, @URL)
IF @Position > 0
SELECT @High = ASCII(UPPER(SUBSTRING(@URL, @Position + 1, 1))) - 48,
@Low = ASCII(UPPER(SUBSTRING(@URL, @Position + 2, 1))) - 48,
@High = @High / 17 * 10 + @High % 17,
@Low = @Low / 17 * 10 + @Low % 17,
@Byte1Value = @Byte1Value + ((16 * @High + @Low) & (POWER(2,6) - 1)) * POWER(2,6),
@URL = STUFF(@URL, @Position, 3, ''),
@Position = PATINDEX(@Pattern, @URL)
IF @Position > 0
BEGIN
SELECT @High = ASCII(UPPER(SUBSTRING(@URL, @Position + 1, 1))) - 48,
@Low = ASCII(UPPER(SUBSTRING(@URL, @Position + 2, 1))) - 48,
@High = @High / 17 * 10 + @High % 17,
@Low = @Low / 17 * 10 + @Low % 17,
@Byte1Value = @Byte1Value + ((16 * @High + @Low) & (POWER(2,6) - 1))
--,@URL = STUFF(@URL, @Position, 3, cast(@Byte1Value as varchar))
--,@Position = PATINDEX(@Pattern, @URL)
SELECT @SurrogateHign = ((@Byte1Value - POWER(16,4)) & (POWER(2,20) - 1)) / POWER(2,10) + 13 * POWER(16,3) + 8 * POWER(16,2),
@SurrogateLow = ((@Byte1Value - POWER(16,4)) & (POWER(2,10) - 1)) + 13 * POWER(16,3) + 12 * POWER(16,2),
@URL = STUFF(@URL, @Position, 3, NCHAR(@SurrogateHign) + NCHAR(@SurrogateLow)),
@Position = PATINDEX(@Pattern, @URL)
END
END
END
RETURN REPLACE(@URL, '+', ' ') END
于 2019-09-05T22:35:57.563 回答
2
create function [dbo].[URLDecode](
@str nvarchar( max )
) returns nvarchar( max )
begin
if @str is null return null
declare @out nvarchar( max ) = N''
set @str = replace( @str, N'+', N'%20' )
while len(@str) > 0
begin
declare @i bigint = patindex( N'%[%][0-9a-fA-F][0-9a-fA-F]%', @str )
if @i = 0 break
set @out = @out + substring( @str, 0, @i ) + convert( nchar(2), convert( varbinary, '0x' + substring( @str, @i + 1, 2 ), 1 ) )
set @str = substring( @str, @i + 3, len(@str) )
end
return @out + @str
end
于 2017-05-18T02:02:03.660 回答
0
我会添加一些额外的解码。我遇到的一个错误是返回值为空。我还注意到上面的一些答案用空格替换了“+”。
ALTER FUNCTION UrlDecode(@url varchar(3072))
RETURNS varchar(3072)
AS BEGIN
DECLARE @count int,
@c char(1),
@cenc char(2),
@i int,
@urlReturn varchar(3072)
SET @count = Len(@url)
SET @i = 1
SET @urlReturn = ''
WHILE (@i <= @count) BEGIN
SET @c = substring(@url, @i, 1)
IF @c LIKE '[!%]' ESCAPE '!' BEGIN
SET @cenc = substring(@url, @i + 1, 2)
SET @c = CHAR(CASE WHEN SUBSTRING(@cenc, 1, 1) LIKE '[0-9]'
THEN CAST(SUBSTRING(@cenc, 1, 1) as int)
ELSE CAST(ASCII(UPPER(SUBSTRING(@cenc, 1, 1)))-55 as int)
END * 16 +
CASE WHEN SUBSTRING(@cenc, 2, 1) LIKE '[0-9]'
THEN CAST(SUBSTRING(@cenc, 2, 1) as int)
ELSE CAST(ASCII(UPPER(SUBSTRING(@cenc, 2, 1)))-55 as int)
END)
SET @urlReturn = @urlReturn + @c
SET @i = @i + 2
END ELSE BEGIN
SET @urlReturn = @urlReturn + @c
END
SET @i = @i +1
END
IF @urlReturn is null BEGIN
set @urlReturn = ''
END ELSE BEGIN
set @urlReturn = REPLACE(@urlReturn, '+', ' ')
END
RETURN @urlReturn
END
GO
于 2019-10-07T17:15:46.407 回答