Need help for sql statement in vb6.0

hi all,

i am trying to write a sql query in vb6.0. i want to exclude some fields in table

for example

if field 1 is empty and field 2 is filled then it should not be counted for record count all other types should be counted

i came to know about "truncate" but i don't know how to use this

pls help me

thanks............