SQL Server Base64函数

IF OBJECT_ID(N'dbo.c_GetUTF8Code') IS NOT NULL

    DROP FUNCTION dbo.c_GetUTF8Code;

GO

CREATE FUNCTION [dbo].[c_GetUTF8Code]   

   (  
       @char Nchar 
   ) 

RETURNS int 

AS 

--UTF8转码 

BEGIN 

 Declare @Code int 
 Select @Code=Cast(Unicode(@char) as int) 
 Declare @Utf8Code int 
 Set @Utf8Code=0 
 if(@Code<128) 
 begin 
  --0-127 
  --0000-007F 
  --0xxxxxxx 
  --01100010 Unocide 
  --01100010 UTF-8 
  Set @Utf8Code=@Code  
 end 
 else if(@Code>127 and @Code<2048) 
 begin 
  --128-2047 
  --0080-07FF 
  --110xxx xx10xx xxxx 
  --110  7      F    F 
  Declare @C1 int 
  Declare @C2 int 
  Declare @C3 int 
  Select @C1=@Code/0x100  
  Select @C2=(@Code%0x100)/0x10 
  Select @C3=@Code%0x10 
  Select @Utf8Code=0xC080+0x400*@C1+0x100*(@C2/4)+0x10*(@C2%4)+@C3 
 end 
 else if(@Code>2047 and @Code<65536) 
 begin 
  --2047-65535 
  --0110 0010 0001 0001 
  --1110 xxxx 10xx xxxx 10xx xxxx 
  --1110 0110 1000 1000 1001 0001 
  Declare @C11 int 
  Declare @C12 int 
  Declare @C13 int 
  Declare @C14 int 
  Select @C11=@Code/0x1000 
  Select @C12=(@Code%0x1000)/0x100 
  Select @C13=(@Code%0x100)/0x10 
  Select @C14=@Code%0x10 
  Select @Utf8Code=0xE08080+0x10000*@C11+0x400*@C12+0x100*(@C13/4)+0x10*(@C13%4)+@C14  
 end 
 return @Utf8Code 
End 

GO 

-------加密函数[dbo].[base64_utf8encode]----

IF OBJECT_ID(N'dbo.base64_utf8encode') IS NOT NULL

    DROP FUNCTION dbo.base64_utf8encode;

GO
 
CREATE FUNCTION [dbo].[base64_utf8encode]   
(   
 @plain_text varchar(max)   
)   

RETURNS varchar(max)   

AS BEGIN 
--Base64解密 
 DECLARE @output varchar(max) 
 DECLARE @block_start integer 
 DECLARE @map char(64)   
 SET @map='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'  
 SET @output='' 
 SET @block_start=0 
 Declare @plain_textLength int 
 Set @plain_textLength=Len(@plain_text) 
 Declare @RestTransfer int--转码数累积 
 Declare @RestTransferLenth int 
 Set @RestTransfer=0 
 Set @RestTransferLenth=0 
 Declare @CodeInt int 
 Declare @block_val BINARY(3) 
 WHILE @block_start<@plain_textLength 
 BEGIN  
  Set @CodeInt=0 
  SELECT @CodeInt= [dbo].[c_GetUTF8Code](SubString(@plain_text,@block_start+1,1)) 
  Declare @CodeTransfer int 
  Set @CodeTransfer=0 
  --0-127 1位 
  --128-2047 2位 
  --2047-65535 3位 
  if(@CodeInt<128) 
  begin 
   --+1位 
   if(@RestTransferLenth=0 or @RestTransferLenth=1) 
   begin 
    Set @RestTransfer=@RestTransfer*0x100+@CodeInt 
    Set @RestTransferLenth=@RestTransferLenth+1 
   end 
   else if(@RestTransferLenth=2) 
   begin 
    Set @CodeTransfer=@RestTransfer*0x100+@CodeInt 
    Set @RestTransfer=0 
    Set @RestTransferLenth=0 
   end 
  end 
  else if(@CodeInt>127 and @CodeInt<2048) 
  begin 
   --+2位 
   if(@RestTransferLenth=0) 
   begin 
    Set @RestTransfer=@CodeInt 
    Set @RestTransferLenth=2 
   end 
   else if(@RestTransferLenth=1) 
   begin 
    Set @CodeTransfer=0x10000*@RestTransfer+@CodeInt 
    Set @RestTransfer=0 
    Set @RestTransferLenth=0 
   end 
   else if(@RestTransferLenth=2) 
   begin 
    Set @CodeTransfer=0x100*@RestTransfer+@CodeInt/0x100 
    Set @RestTransfer=@CodeInt%0x100 
    Set @RestTransferLenth=1 
   end 
  end 
  else if(@CodeInt>2047) 
  begin 
   --+3位 
   if(@RestTransferLenth=0) 
   begin 
    Set @CodeTransfer=@CodeInt 
    Set @RestTransfer=0 
    Set @RestTransferLenth=0 
   end 
   else if(@RestTransferLenth=1) 
   begin 
    Set @CodeTransfer=0x10000*@RestTransfer+@CodeInt/0x100 
    Set @RestTransfer=@CodeInt%0x100 
    Set @RestTransferLenth=1 
   end 
   else if(@RestTransferLenth=2) 
   begin 
    --剩余部分十六进制右移两位与新数据前两位之和 
    Set @CodeTransfer=0x100*@RestTransfer+@CodeInt/0x10000 
    Set @RestTransfer=@CodeInt%0x10000 
    Set @RestTransferLenth=2 
   end 
  end 
  ---累积到3位，执行加密转换 
  if(@CodeTransfer>0x100000) 
  begin 
   SET @block_val = CAST(@CodeTransfer AS BINARY(3))   
   SET @output = @output 
   + SUBSTRING(@map , @block_val/262144  +1,1) 
   + SUBSTRING(@map ,(@block_val/4096&63)+1,1) 
   + SUBSTRING(@map ,(@block_val/64  &63)+1,1) 
   + SUBSTRING(@map ,(@block_val&63)     +1,1) 
  end 
  SET @block_start=@block_start+1   
 END  
 IF @RestTransferLenth>0   
  BEGIN  
  SET @block_val=Cast(@RestTransfer*(Case @RestTransferLenth When 1 Then 65536 Else 256 end) as BINARY(3)) 
  SET @output=@output  
   +SUBSTRING(@map , @block_val/262144+1,    1)   
   +SUBSTRING(@map ,(@block_val/4096  &63)+1,1)   
   +CASE WHEN @RestTransferLenth =1 
   THEN REPLACE(SUBSTRING(@map ,(@block_val/64&63)+1,1),'A','=')   
   ELSE SUBSTRING(@map ,(@block_val/64&63)+1,1) 
    END 
   +CASE WHEN @RestTransferLenth=1   
   THEN '='  
   ELSE REPLACE(SUBSTRING(@map ,(@block_val&63)+1,1),'A','=') 
    END  
  END 
 RETURN @output  
END 

GO 
----------解密函数----------
IF OBJECT_ID(N'dbo.base64_utf8decode') IS NOT NULL

    DROP FUNCTION dbo.base64_utf8decode;

GO

CREATE FUNCTION [dbo].[base64_utf8decode]   
   (   
       @encoded_text varchar(max)   
   )   
   RETURNS varchar(max)   

   AS BEGIN 

--BASE64加密 
DECLARE @output varchar(max) 
DECLARE @block_start int 
DECLARE @encoded_length int 
DECLARE @decoded_length int 
DECLARE @mapr binary(122)   
 
SET @output = ''  
SET @mapr =   
  0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF    --    1-33   
  +0xFFFFFFFFFFFFFFFFFFFF3EFFFFFF3F3435363738393A3B3C3DFFFFFF00FFFFFF    --    33-64   
  +0x000102030405060708090A0B0C0D0E0F10111213141516171819FFFFFFFFFFFF    --    65-96   
  +0x1A1B1C1D1E1F202122232425262728292A2B2C2D2E2F30313233--    97-122   
SET @encoded_length=LEN(@encoded_text)   
SET @decoded_length=@encoded_length/4*3 
SET @block_start=1   
Declare @Code int 
Set @Code=0 
Declare @CodeLength int--累计连接数，1，2，3 
Set @CodeLength =0 
WHILE @block_start<@encoded_length 
BEGIN 
 Declare @Integer Integer 
 Set @Integer=substring(@mapr,Unicode(substring(@encoded_text,@block_start  ,1)),1)*262144   
     + substring(@mapr,Unicode(substring(@encoded_text,@block_start+1,1)),1)*4096   
     + substring(@mapr,Unicode(substring(@encoded_text,@block_start+2,1)),1)*64   
     + substring(@mapr,Unicode(substring(@encoded_text,@block_start+3,1)),1) 

 Declare @C1 int 
 Declare @C2 int 
 Declare @C3 int 
 --0xFF FF FF 
 Set @C1=@Integer/0x10000 
 Set @C2=(@Integer/0x100)%0x100 
 Set @C3=@Integer%0x100 
 -------------------------------------@C1 
 if(@C1<0x80) 
 begin 
  if(@CodeLength=2) 
  begin 
   --128-2047 
   --0080-07FF 
   --110x xx xx 10xx xxxx 
   Set @Code=((@Code%0x2000)/0x100)*0x10+@Code%0x40 
   SET @output=@output+NCHAR(@Code) 
   --print @Code  
   Set @Code=0 
   Set @CodeLength=0 
  end 
  SET @output=@output+CAST(Cast(@C1 AS BINARY(1))AS VARCHAR(1)) 
 end 
 else 
 begin 
  --码字连接 
  Set @Code=@Code*0x100+@C1 
  SET @CodeLength=@CodeLength+1 
  if(@CodeLength=3) 
  begin 
   --0110 0010 0001 0001 
   --1110 xxxx 10xx xxxx 10xx xxxx 
   --1110 0110 1000 1000 1001 0001 
   Set @Code=((@Code%0x100000)/0x10000)*0x1000+((@Code%0x4000)/0x100)*0x40+@Code%0x40 
   SET @output=@output+NCHAR(@Code) 
   Set @Code=0 
   Set @CodeLength=0 
  end 
 end 

 -------------------------------------@C2 
 if(@C2<0x80) 
 begin 
  if(@CodeLength=2) 
  begin 
   --128-2047 
   --0080-07FF 
   --110x xx xx 10xx xxxx 
   Set @Code=((@Code%0x2000)/0x100)*0x10+@Code%0x40 
   SET @output=@output+NCHAR(@Code) 
   --print @Code  
   Set @Code=0 
   Set @CodeLength=0 
  end 
  SET @output=@output+CAST(Cast(@C2 AS BINARY(1))AS VARCHAR(1)) 
 end 
 else 
 begin 
  --码字连接 
  Set @Code=@Code*0x100+@C2 
  SET @CodeLength=@CodeLength+1 
  if(@CodeLength=3) 
  begin 
   --0110 0010 0001 0001 
   --1110 xxxx 10xx xxxx 10xx xxxx 
   --1110 0110 1000 1000 1001 0001 
   Set @Code=((@Code%0x100000)/0x10000)*0x1000+((@Code%0x4000)/0x100)*0x40+@Code%0x40 
   SET @output=@output+NCHAR(@Code) 
   Set @Code=0 
   Set @CodeLength=0 
  end 
 end 
 -------------------------------------@C3 
 if(@C3<0x80) 
 begin 
  if(@CodeLength=2) 
  begin 
   --128-2047 
   --0080-07FF 
   --110x xx xx 10xx xxxx 
   Set @Code=((@Code%0x2000)/0x100)*0x10+@Code%0x40 
   SET @output=@output+NCHAR(@Code) 
   --print @Code  
   Set @Code=0 
   Set @CodeLength=0 
  end 
  SET @output=@output+CAST(Cast(@C3 AS BINARY(1))AS VARCHAR(1)) 
 end 
 else 
 begin 
  --码字连接 
  Set @Code=@Code*0x100+@C3 
  SET @CodeLength=@CodeLength+1 
  if(@CodeLength=3) 
  begin 
   --0110 0010 0001 0001 
   --1110 xxxx 10xx xxxx 10xx xxxx 
   --1110 0110 1000 1000 1001 0001 
   Set @Code=((@Code%0x100000)/0x10000)*0x1000+((@Code%0x4000)/0x100)*0x40+@Code%0x40 
   SET @output=@output+NCHAR(@Code) 
   Set @Code=0 
   Set @CodeLength=0 
  end 
 end 
 SET @block_start = @block_start + 4   
END  
IF RIGHT(@encoded_text,2)='==' 
 SET @decoded_length=@decoded_length-2 
ELSE IF RIGHT(@encoded_text,1)='=' 
 SET @decoded_length=@decoded_length-1 
RETURN LEFT(@output ,@decoded_length)   
END