c# - Dynamic SQL always output the same data -

i got serious problem. problem have 3 checkbox in form (c#) :

apple orange banana 

here's short sql snippet:

and (          <isnotempty property="apple">           m.supplier = 'a' or         </isnotempty>         <isnotempty property="orange">           m.supplier = 'b' or         </isnotempty>         <isnotempty property="banana">           (m.supplier != 'a' , m.supplier != 'b')         </isnotempty> ) 

so want want view apple data if uncheck orange , banana checkbox or if check orange checkbox show orange data only. problem code output same data if check or uncheck them.

thanks in advance guys.