Generating random strings with T-SQL

Question

If you wanted to generate a pseudorandom alphanumeric string using T-SQL, how would you do it? How would you exclude characters like dollar signs, dashes, and slashes from

Answer 1

In SQL Server 2012+ we could concatenate the binaries of some (G)UIDs and then do a base64 conversion on the result.

SELECT 
    textLen.textLen
,   left((
        select  CAST(newid() as varbinary(max)) + CAST(newid() as varbinary(max)) 
        where   textLen.textLen is not null /*force evaluation for each outer query row*/ 
        FOR XML PATH(''), BINARY BASE64
    ),textLen.textLen)   as  randomText
FROM ( values (2),(4),(48) ) as textLen(textLen)    --define lengths here
;

If you need longer strings (or you see = characters in the result) you need to add more + CAST(newid() as varbinary(max)) in the sub select.