USE pubs
GO
declare @a int, @b int, @rand_num int, @table_name varchar( 50 ), @pk_field_name varchar( 50 )
set @a =  1 
set @table_name = 'authors'
set @pk_field_name = 'au_id'

select @b=rows
from sysindexes a 
inner join sysobjects b on b.id = a.id
where indid IN( 0 ,  1 ) and b.name = @table_name and b.xtype = 'U'

 /*Random number between 1 and total table record count*/ 
set @rand_num = cast((@b-@a+ 1 )*RAND()+@a as int)

 --select @a, @b, @rand_num
 
declare @mysql varchar( 4000 )
set @mysql = 'select top 1 '+@pk_field_name+' from (select top '+CAST(@rand_num AS varchar)
+' '+@pk_field_name+' from '+@table_name+' order by '+@pk_field_name+') AS a order by '+@pk_field_name+' desc'
exec(@mysql)