SQL加密

   
     

    
      use
    
       Tempdb 
    
      go
    
       
    
      if
    
       
    
      object_ID
    
      (
    
      '
    
      fn_ACITEncryption
    
      '
    
      ) 
    
      is
    
       
    
      not
    
       
    
      null
    
       
    
      drop
    
       
    
      function
    
       fn_ACITEncryption 
    
      go
    
       
    
      create
    
       
    
      function
    
       fn_ACITEncryption ( 
    
      @Str
    
       
    
      nvarchar
    
      (
    
      4000
    
      ),
    
      --
    
      加密的字符串
    
       
    
       
    
      @Flag
    
       
    
      bit
    
      =
    
      1
    
      ,
    
      --
    
      1、加密 0、解密
    
       
    
       
    
      @Key
    
       
    
      nvarchar
    
      (
    
      50
    
      )
    
      --
    
      密文
    
       
    
      ) 
    
      returns
    
       
    
      nvarchar
    
      (
    
      4000
    
      )
    
      --
    
      這里可轉換成二進制
    
       
    
      with
    
       Encryption 
    
      as
    
       
    
      begin
    
       
    
      Declare
    
       
    
      @LenStr
    
       
    
      int
    
      ,
    
      @i
    
       
    
      int
    
      ,
    
      @Str2
    
       
    
      nvarchar
    
      (
    
      4000
    
      ),
    
      @Split
    
       
    
      nvarchar
    
      (
    
      2
    
      ),
    
      @LenKey
    
       
    
      int
    
       
    
      select
    
       
    
      @Str
    
      =
    
      @Str
    
      +
    
      '
    
      A
    
      '
    
      ,
    
      @LenStr
    
      =
    
      len
    
      (
    
      @Str
    
      ),
    
      @i
    
      =
    
      1
    
      ,
    
      @Str2
    
      =
    
      ''
    
      ,
    
      @LenKey
    
      =
    
      Len
    
      (
    
      @Key
    
      +
    
      '
    
      A
    
      '
    
      )
    
      -
    
      1
    
       
    
      while
    
       
    
      @i
    
      <
    
      @LenStr
    
       
    
      select
    
       
    
      @Split
    
      =
    
      substring
    
      (
    
      @Str
    
      ,
    
      @i
    
      ,
    
      1
    
      ), 
    
      @Split
    
      =
    
      nchar
    
      ((
    
      unicode
    
      (
    
      @Split
    
      )
    
      +
    
      case
    
       
    
      @Flag
    
       
    
      when
    
       
    
      1
    
       
    
      then
    
       
    
      unicode
    
      (
    
      substring
    
      (
    
      @Key
    
      +
    
      '
    
      A
    
      '
    
      ,
    
      @i
    
      %
    
      @LenKey
    
      +
    
      1
    
      ,
    
      1
    
      ))
    
      -
    
      1
    
       
    
      when
    
       
    
      0
    
       
    
      then
    
       
    
      65535
    
      -
    
      unicode
    
      (
    
      substring
    
      (
    
      @Key
    
      +
    
      '
    
      A
    
      '
    
      ,
    
      @i
    
      %
    
      @LenKey
    
      +
    
      1
    
      ,
    
      1
    
      )) 
    
      else
    
       
    
      0
    
       
    
      end
    
      )
    
      %
    
      65535
    
      +
    
      cast
    
      (
    
      @Flag
    
       
    
      as
    
       
    
      int
    
      )), 
    
      @Str2
    
      =
    
      @Str2
    
      +
    
      @Split
    
      ,
    
      @i
    
      =
    
      @i
    
      +
    
      1
    
       
    
      return
    
       
    
      @Str2
    
       
    
      end
    
       
    
      go
    
       
    
      select
    
       dbo.fn_ACITEncryption(N
    
      '
    
      Roy
    
      '
    
      ,
    
      1
    
      ,
    
      '
    
      123
    
      '
    
      ) 
    
      as
    
       加密后字符串 
    
      /*
    
       加密后字符串 ------------------------------ „¢ª (1 個資料列受到影響) 
    
      */
    
       
    
      select
    
       dbo.fn_ACITEncryption(N
    
      '
    
      㢻
    
      '
    
      ,
    
      0
    
      ,
    
      '
    
      123
    
      '
    
      ) 
    
      as
    
       解密后字符串 
    
      /*
    
       解密后字符串 -------------------------- Roy (1 個資料列受到影響) 
    
      */
    
       
   
     

http://blog.csdn.net/roy_88/archive/2009/11/12/4801917.aspx