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 native function exist? If not, what's the best way to do Base64 encoding in T-SQL?
I know this has already been answered, but I just spent more time than I care to admit coming up with single-line SQL statements to accomplish this, so I'll share them here in case anyone else needs to do the same:
-- Encode the string "TestData" in Base64 to get "VGVzdERhdGE="
SELECT
CAST(N'' AS XML).value(
'xs:base64Binary(xs:hexBinary(sql:column("bin")))'
, 'VARCHAR(MAX)'
) Base64Encoding
FROM (
SELECT CAST('TestData' AS VARBINARY(MAX)) AS bin
) AS bin_sql_server_temp;
-- Decode the Base64-encoded string "VGVzdERhdGE=" to get back "TestData"
SELECT
CAST(
CAST(N'' AS XML).value(
'xs:base64Binary("VGVzdERhdGE=")'
, 'VARBINARY(MAX)'
)
AS VARCHAR(MAX)
) ASCIIEncoding
;
I had to use a subquery-generated table in the first (encoding) query because I couldn't find any way to convert the original value ("TestData") to its hex string representation ("5465737444617461") to include as the argument to xs:hexBinary() in the XQuery statement.