Generate MD5 hash string with T-SQL

Question

Is there a way to generate MD5 Hash string of type varchar(32) without using fn_varbintohexstr

SUBSTRING(master.dbo.fn_varbintohexstr(HashBytes(\'MD5\', \'em         


        

Answer 1

declare @hash nvarchar(50)
--declare @hash varchar(50)

set @hash = '1111111-2;20190110143334;001'  -- result a5cd84bfc56e245bbf81210f05b7f65f
declare @value varbinary(max);
set @value = convert(varbinary(max),@hash);


select  
 SUBSTRING(sys.fn_sqlvarbasetostr(HASHBYTES('MD5', '1111111-2;20190110143334;001')),3,32) as 'OK'
,SUBSTRING(sys.fn_sqlvarbasetostr(HASHBYTES('MD5', @hash)),3,32) as 'ERROR_01'
,SUBSTRING(sys.fn_sqlvarbasetostr(HASHBYTES('MD5',convert(varbinary(max),@hash))),3,32) as 'ERROR_02'
,SUBSTRING(sys.fn_sqlvarbasetostr(sys.fn_repl_hash_binary(convert(varbinary(max),@hash))),3,32)
,SUBSTRING(sys.fn_sqlvarbasetostr(master.sys.fn_repl_hash_binary(@value)),3,32)

Answer 2

For data up to 8000 characters use:

CONVERT(VARCHAR(32), HashBytes('MD5', 'email@dot.com'), 2)

Demo

For binary data (without the limit of 8000 bytes) use:

CONVERT(VARCHAR(32), master.sys.fn_repl_hash_binary(@binary_data), 2)

Demo

Answer 3

You didn't explicitly say you wanted the string to be hex; if you are open to the more space efficient base 64 string encoding, and you are using SQL Server 2016 or later, here's an alternative:

select SubString(h, 1, 32) from OpenJson(
    (select HashBytes('MD5', 'email@dot.com') h for json path)
) with (h nvarchar(max));

This produces:

9TvQiSDl0lgJ3yVj75xStg==