Sqlserver 自定義實用函數集(不定期更新)

1. 刪除字符串中符合正規表達的字符

CREATE FUNCTION fun_regex_del 
(
    @inStr VARCHAR(MAX),
    @expression VARCHAR(MAX)
)
RETURNS VARCHAR(MAX)
AS
BEGIN
    DECLARE @str_userlist VARCHAR(MAX);
    SET @str_userlist = @inStr;

    DECLARE @i INT;
    SET @i = 0;

    WHILE PATINDEX(@expression,@str_userlist) > 0  
    BEGIN  
        SET @i = PATINDEX(@expression,@str_userlist)  
        SET @str_userlist = STUFF(@str_userlist,@i,1,'')  
    END   

    RETURN @str_userlist;
END

GO

2. URLDecode

CREATE FUNCTION [dbo].[SP_fnURLDecode] ( @input NVARCHAR(4000) )
RETURNS NVARCHAR(4000)
AS 
    BEGIN 

        DECLARE @char NVARCHAR(4)
        DECLARE @asc NVARCHAR(4)
        DECLARE @asc2 NVARCHAR(4)

        WHILE ( CHARINDEX('%', @input) > 0 ) 
            BEGIN
                SET @char = ( SELECT    SUBSTRING(@input,
                                                  CHARINDEX('%', @input) + 1,
                                                  2)
                            )
                IF ( ISNUMERIC(SUBSTRING(@char, 1, 1)) ) > 0 
                    BEGIN
                        SET @asc = ( SELECT CAST(SUBSTRING(@char, 1, 1) AS INT)
                                   ) * 16
                    END
                ELSE 
                    BEGIN 
                        SET @asc = ( SELECT ASCII(CAST(SUBSTRING(@char, 1, 1) AS CHAR))
                                   ) - 55
                        SET @asc = ( SELECT @asc * 16
                                   )
                    END
                IF ( ISNUMERIC(SUBSTRING(@char, 2, 1)) ) > 0 
                    SET @asc = ( SELECT CAST(@asc AS INT)
                                        + ( SELECT  CAST(SUBSTRING(@char, 2, 1) AS INT)
                                          )
                               )
                ELSE 
                    BEGIN 
                        SET @asc2 = ( SELECT    ASCII(CAST(SUBSTRING(@char, 2,
                                                              1) AS CHAR))
                                    ) - 55
                        SET @asc = ( SELECT CAST(@asc AS INT)
                                            + ( SELECT  CAST(@asc2 AS INT)
                                              )
                                   )
                    END
                SET @input = ( SELECT   SUBSTRING(@input, 0,
                                                  CHARINDEX('%', @input))
                             ) + CHAR(@asc)
                    + ( SELECT  SUBSTRING(@input, CHARINDEX('%', @input) + 3,
                                          LEN(@input))
                      )
            END
        RETURN @input
    END


GO