Base64 encoding in SQL Server 2005 T-SQL

Question

I\'d like to write a T-SQL query where I encode a string as a Base64 string. Surprisingly, I can\'t find any native T-SQL functions for doing Base64 encoding. Does a nativ

Answer 1

Here's a modification to mercurial's answer that uses the subquery on the decode as well, allowing the use of variables in both instances.

DECLARE
    @EncodeIn VARCHAR(100) = 'Test String In',
    @EncodeOut VARCHAR(500),
    @DecodeOut VARCHAR(200)    

SELECT @EncodeOut = 
    CAST(N'' AS XML).value(
          'xs:base64Binary(xs:hexBinary(sql:column("bin")))'
        , 'VARCHAR(MAX)'
    )
FROM (
    SELECT CAST(@EncodeIn AS VARBINARY(MAX)) AS bin
) AS bin_sql_server_temp;

PRINT @EncodeOut

SELECT @DecodeOut = 
CAST(
    CAST(N'' AS XML).value(
        'xs:base64Binary(sql:column("bin"))'
      , 'VARBINARY(MAX)'
    ) 
    AS VARCHAR(MAX)
) 
FROM (
    SELECT CAST(@EncodeOut AS VARCHAR(MAX)) AS bin
) AS bin_sql_server_temp;

PRINT @DecodeOut