but the same will not return any rows when we use

select * from #temp where code ='0'

this will return nothing.When we use 0 in quotes it will not return any no of rows.Implicits conversion happens from varchar to int.but it will not happen from int to varchar.We want to convert explicitly.

select * from #temp where code =convert(int,'0')

this will return three rows even we put zero in sigle quotes.