Question

I have to log some param values to a log file (SQL Server 2005)

Is there an universal .ToString() method in SQL that could convert any kind of object to string in order to visualize a object value?

by eg. if I use STR(@param) it expects that @param be an float or integer value. and it fails when the @param is a varchar…

Answer 1

You should be able to convert any parameter to a string using CONVERT() or CAST():

SELECT CONVERT(NVARCHAR(MAX), @param);
SELECT CAST(@param AS NVARCHAR(MAX));

Whether the conversion is meaningful is another thing.